The United States and Greenland: Episodes in Nuclear History, 1957-1968
Part II: The B-52 Crash and Its Impact

The JCS Chairman’s 1955 proposal for the purchase of Greenland may have never received a formal Department of State response, but a new JCS proposition in 1956 to either purchase or lease it for 99 years encountered a formal and highly negative State Department response. According to the critique by Ambassador to Denmark Robert Coe and Assistant Secretary of State C. Burke Elbrick, a U.S. proposal to purchase Greenland “could well be regarded as an insult by the Danes and could be seriously damaging to U.S.-Danish relations.” That line of argument flowed from Elbrick and Coe’s understanding of the history of Denmark’s economic interests in Greenland, its territorial policy and its “paternalistic—‘white man’s burden’”—approach to the Inuit, the nature of the 1951 U.S.-Denmark defense agreement, and U.S. security interests. The Elbrick/Coe presentation tracks with William Kerrigan’s critical analysis of JCS proposals in Part I of this posting but with more detail.

The JCS’s proposal did not show up in the file that included the State Department’s critique and it has not yet been found at the National Archives.

A day before Robert McNamara called him about the B-52 crash, President Johnson learned about it through a memo from the Situation Room staff. According to the memo, preparations were in the works to send an “ordnance disposal team to the crash site to handle the nuclear weapons.” The undated memorandum included information indicating that the B-52 was on a “normal airborne alert mission” before it declared an emergency because of a fire on board, although with no specific reference to the BMEWS monitoring task.

This message was written in response to standard questions, found in 4 AFR [Air Force Regulation] 127-4, about incidents involving aircraft. A copy of the Air Force regulation is not available, but this report includes an early account of what caused the crash and the condition of each of the crew members, who had all been found, including the one fatality. According to the report, the B-52 was in “Thule orbit at 33,000 feet.” That indicated why the plane crashed near the air base, although whether White House officials shared the information with President Johnson is not known.

Although dated 18 March 1968, Bruner’s report described his experience in Greenland soon after the crash. He and Los Alamos plutonium expert Wright Langham hurriedly traveled to Thule Air Force Base to inspect the crash site. This is Bruner’s account of the trip, what he learned about the crash and efforts to determine the area of contamination, and the interactions with Danish scientists and naturalists.

While waiting for the flight, Bruner and Langham ran into Thule Air Base Commander, Col. C.S. Dresser who briefed them on Thule and Greenland, including the phenomenon of “phases,” the local name for ice storms that create dangerous and deadly “white outs.” Bruner learned on the spot that after the crash, a series of phases had enlarged the contaminated area. Bruner provided granular detail on the tremendously difficult conditions—total darkness and lethal cold—that U.S. Air force officers and troops endured while conducting the search for bomb debris.

From speaking with the naturalists, characterized here as “old Greenland hands,” Bruner developed a “composite-summary of information about the bio-ecology” of the area, with considerable detail on the way of life of the Inuit people, their hunting patterns, and their diet. According to Bruner, “These ecological considerations dictated that the contaminated metal and black streak would have to be removed and buried, probably in the U.S.” He took note of what he saw as sincere concerns on the part of the Danes “about the possibility of Pu [plutonium] getting into the food chains on which the Greenlanders depend.” In memoranda on possible biological surveillance programs [See Annexes IV and V], Bruner observed that, “The Danish Government has a very paternalistic policy toward the Greenlanders and appears determined to look out for their interests as much or more than they would for themselves.”[5]

Seaborg called Hans C. Koch, the chief of Denmark’s Atomic Energy Commission, telling him that “we … saw no reason for alarm.” The U.S. AEC would take a “detailed, scientific” approach to environmental and other matters and would “be in touch to exchange views” with the Danes. “Koch said they are not really alarmed but are doing everything to keep things quiet.” According to Dr. Harry Bruner, that conversation was important for helping create a “cooperative, genial attitude of the Danes… They appreciated his sincerity and responded in kind.” [See Document 8].

When Danish scientists met with U.S. officials in Greenland, their chief concern was “possible contamination of the natural food supply” for some 200 Inuit families living near North Star Bay. While acknowledging that under international standards that the distribution of the weapons plutonium into a cubic kilometer of the bay’s water would be safe, the Danes wanted “zero contamination.” Taking a “fairly hard line,” they favored “scraping up the contaminated layers of ice and snow and doing something with it.”

This not a record of the DoD-AEC briefing, except on one significant point: the scope of plutonium contamination: “38 % of the total plutonium burden has been located on the snow and ice around the site of the crash; 36% is within the [unclear words] corresponding to 100,000 counts per minutes as measured on the available instrumentation.” The area of black ice, some 20 acres, was the location of 95 percent of the plutonium contamination.

Assistant to the Secretary of Defense for Atomic Energy Carl Walske wanted the panel to consider areas where “action might be taken fairly promptly,” relating to three issues: the radiological situation, the cleanup, and the definition of an environmental monitoring program. A key consideration was that the area of black ice “will be completely gone by July and will begin to break up in April.” If a decision to remove the ice, snow, and debris was to be made, it would be necessary to so by 1 April: “time is of the essence.”

In the discussion of the radiological situation, the panelists, who included Wright Langham, believed it “very probably quite safe to allow the whole residual contamination on the ice to drop into the water and be dispersed as the ice melts.” Yet, in the discussion of cleanup issues, the panelists assumed that “a vigorous attempt to remove this main contamination would be well received by the Danes.” Moreover, the “Panel is not wholly charmed by calculations which might suggest permissible contamination of the sea water,” which would be the case if the plutonium-polluted ice melted into the bay.

As for biological-environmental monitoring, the Panelists agreed that before plutonium passed to larger animals and humans, it would be first observable in “detritus, algae, plankton, or a few specific animals such as the mussel.” The Panel suggested monitoring “emphasize these aspects rather than the extensive collection and examination of larger animals.”

In his account of meetings held in Copenhagen, Bruner reported on the internal U.S. discussions held before the talks with Danish scientists. A key item was determining the extent of contamination of the scar area where the plane crashed. Wright Langham had studied the black crust of the scar area and had determined that it was a “combination of JP [jet propellant]-4 kerosene fuel, carbon, very fine debris, and organic matter in which is entrapped about 80% of the PU [plutonium] of the total sample.” During this discussion, Bruner reported that the Danes favored an “extensive biosurveillance program to assure that the Greenlander [Inuit] would not be contaminated by PU.” At the end of the meeting, the participants decided to “urge the Danes first to state what they thought should be done.”

During the talks with Danish officials, Langham suggested that “biological hazards would be minimal due to the dilution of the PU” and that there “should be no harm to anything if the PU were kept out of the systematic circulation of animals.” What concerned the Danes was that the JP-4 would form a slick, because an “oil slick will move at 5% of the wind velocity, the film would pile up on the shore of Saunders Island, where there are birds, walrus and seals in the summer.” The Danes saw that as a “major problem” because the movement of the slick was “unpredictable.” The implication was that there should be no fuel “to form a slick.” According to Bruner, that was “another way of saying: We want you to scrape up all the contaminated ice and do something with it.” According to Bruner’s 19 April report and the SAC “Crested Ice” history, the U.S. and the Danes then reached a “gentleman’s agreement” based on that point: the U.S. would remove the contaminated aircraft debris and snow and ice, an estimated 10,000 cubic meters, in the range of 90 to 95 percent of the total contamination, for storage in sealed containers for eventual removal.

Giller kept the AEC up to date on the collection of aircraft and weapons debris and the efforts to remove contaminated ice and snow. According to Giller’s report, the “last piece of positively identified weapons debris was found on February 14.” A postmortem on the weapons debris had to determine what pieces belong to which weapons “in order to ascertain what happened to the fourth weapon secondary, from which no parts have been positively identified.”

Giller also reviewed the plans to scrap the top five inches of ice and snow from the impact area, which would comprise 100,000 cubic feet, noting that Oak Ridge was “prepared to dispose of this material, possibly in 25,000 gallon tanks.” During the recent talks in Copenhagen, the Danes proposed “to conduct all monitoring and surveillance studies of the biota of the area using the logistic support of Thule Air Base and leaving to the Air Force the task of removing the debris and scraping up snow and ice in the contaminated areas.” That was the essence of the “gentleman’s agreement.”

This Executive Session included Committee members and representatives from the Air Force, the Department of Defense, and the AEC. The briefings, led by Walske, General Hunziker, and Langham, covered the accident itself, the search for aircraft and weapons debris and the cleanup efforts, and the plans to remove the barrels of contaminated debris and ice. Langham emphasized that “as far as I am concerned out on this big cake of ice which is going to break up and melt into the bay … before long there is absolutely no risk whatsoever, particularly now that we have cleaned up 93 percent of it.”

For Walske, the cleanup effort was in the “nature of precautionary, super-precautionary … work” that “brought us a lot of good will from the Danes.” While the briefers downplayed the risk of plutonium contamination, Walske acknowledged “that the U.S. could not say “unequivocally to the Danes that the engine oil when it melted in the summertime wouldn’t go over the shore and carry plutonium there.” Langham minimized the actual hazard but quoted one of the Danes, who “aptly put it, ‘Don’t dump your garbage in someone else’s doorway and walk away if you get caught.’” As Langham put it “there is no “way that you can hide the fact that you had an incident involving nuclear weapons.”

The JCAE members were sympathetic. Senator Burke Hickenlooper (R-IA) “realize[d] the benefits of bending over backwards to assure our hosts that we are not going to contaminate their population nor their food supply... I think it is worth the extra expense.” But he was surprised to learn from a statement made by General Ottto Glasser that the Danes were concerned about the “propaganda activities” of other countries, presumably the Soviet Union and its allies, and that they wanted to “bend over backwards to do a good job [to] blunt” propaganda.

Bruner’s detailed report on a “cordial” meeting at the Pentagon with Danish representatives included General Hunziker’s briefing on the cleanup. So far, about 230,000 cubic of blackened ice had been transported to the shore and stored in 65 steel tanks. As of 1 March, about 83 percent of the total Pu on the ice had been removed but “if only the black streak area and the cracked ice are considered then about 93% has been removed.” Hunziker further reported that the “blackened area is no longer discernible” but that up to 100 gallons of JP fuel and 350 grams of Pu were still in the ice, but that patrolling the shore for pieces of airplane, oil, and contamination would catch some of the contamination. The cleanup work that Hunziker was describing was Phase II of Operation Crested Ice, which officially began on 3 March (see Crested Ice history, Document 13).

Also discussed during the meeting was Langham’s reconstruction of the B-52 crash and the possibility of further surveillance of the areas that had been contaminated. The Danes wanted to handle it themselves in a “low-key” way because if foreigners were involved it would undermine statements to the Greenlanders that the bay was “suitable for hunting and travel.”

The Air Force had before it the problem of disposing of 10,500 “measurement tons” of melted ice and snow sealed in 232 1,800-gallon tanks and a “wide variety of sealed containers of contaminated solid residue, primarily aircraft parts.” The goal was to remove the material from Greenland as soon as possible. After the staff of the Division of Military Applications reviewed possible sites for storing the material, including AEC facilities at Savannah River, Oak Ridge, Richland, and the Nevada Test Site, and looked closely at pros and cons and the expenses involved, it concluded that “from an overall standpoint, the best solution is to dispose of all the residue at the Savannah River Plant.” Curtailing overland transport of the material was an important consideration. Moreover, to minimize any danger of a criticality incident, the Savannah River operation had a “capability to effect positive containment of the plutonium in the liquid residue.” The estimated total cost, including transportation and disposal, was over $1.2 million (1968 dollars).

This is a detailed account of SAC’s role in the cleanup after the Thule accident from January to early April 1968. It includes a description of the accident on 22 January, the assembly of the disaster control team at Thule Air Bases, and the two main phases of “Crested Ice.” Information concerning Phase I, on the recovery of bomb and aircraft debris, is wholly excised from this version. Nevertheless, this account provides useful coverage of Phase II, from late January through early April, including the negotiations with Danish scientists and officials toward the “gentleman’s agreement” and the cleanup and removal of contaminated material.

Unfortunately, in response to an Archive request for a new declassification review of this history, the Air Force has been unable to find the original classified version.

This special edition of USAF Nuclear Safety provided detailed, if carefully vetted, coverage of the Thule accident. It covered the cleanup work, the ecological considerations, the role of public affairs, and the removal of the contaminated debris. It also provided considerable information on the role of Danish scientists and U.S. interactions with them. But it also provided a cover story—for example, treating the underwater investigation as a search for radioactivity instead of missing bomb parts. Also elided was why an airborne alert B-52 happened to be flying near Thule. That remained a secret for years.

As Giller mentioned in his 23 February report, the weapons recovery efforts had not found the “secondary” for the fourth bomb. Apparently one of the missing pieces was a compact uranium rod, the cylinder-shaped fissile core of the weapons’ thermonuclear secondary (fusion) stage—its “spark plug.” A major study by Svend Aage Kristensen reviewed the search for weapons parts and carefully assessed the claims, repeated over the years, that there was a missing bomb. Kristensen found that the declassified evidence did not indicate any concern about a missing bomb, but pinpointed a lost uranium fissile core, resembling a “marshal’s baton,” that was a crucial element of the weapon’s secondary stage.[6]

Giller informed the Commission members that the Defense Department sought the AEC’s “consensus” on the suitability and the possible extent of an underwater search for missing bomb parts. As he mentioned, the “gentleman’s agreement” covered the possibility of a sea-bottom search of which the U.S. would inform the Danes of any results. The Air Force had commissioned a Navy study to evaluate possible methods of searching underwater. The Air Force did not “anticipate a very complicated search since the water is relatively shallow (approximately 600 feet at the most) and the bottom of the bay has the characteristics of a small desert.”

The Department of Defense was willing to support a “brief underwater survey” to determine the extent of a search. While an extensive search might be unsuccessful, “even a brief search might find sensitive classified debris which another nation might recover if we did not.”

Giller forwarded to the AEC a Sandia study of an estimated “footprint” for the underwater trajectories of the missing weapons parts and further defined the “suggested search area with probabilities” of success.

After a presentation by Ocean Systems, Inc., on 9 May 1968, the Air Force had decided to support a “survey of the ocean bottom” near Thule using a “submersible deep sea diver.” The Air Force would cover the Navy’s costs after the completion of the operation.

The State Department informed the Embassy of the plan to deploy the Star III submersible to survey the bottom of North Star Bay. The “primary and confidential purpose of survey … is to assure that no visible and recoverable sensitive parts of the nuclear devices are on the bottom.” The U.S. would give the Danish government and the press a different explanation, treating the survey as part of a “US/Danish summer observation program, with Danes conducting surface effort and US sub-surface, in order to do everything physically possible to assure that no hazards exist in the area.”

Anticipating “speculation … in Danish and international press that survey is really effort to find missing bomb or important components,” the project “would require approval highest levels Danish Government, and especially well thought

out scenario for public affairs treatment.” In the “unlikely event” of the discovery of “significant and recoverable bomb parts,” a U.S Navy salvage vessel would go to Thule “almost immediately to undertake recovery,” which would “require new press guidance.”

Ambassador White agreed that with the Department that the U.S. could treat the Star III survey as a program of continuation of the “arrangements and obligations of B-52 crash program.” White recommended that the U.S. begin exploratory talks with Hans Koch of the Danish AEC because his suggestions in “dealing with Danish press and other Danish repercussion of B-52 .... proved sound.” Koch is a “close friend who has proved discreet.” He “assisted in keeping publicity about clean-up operations well channeled, reasonable, and even helpful to U.S. efforts.” State Department messages endorsed the Ambassador’s recommendations and authorized follow-up action.

The Open-Net includes numerous reports on the Star III operations in North Star Bay during August 1968. This report conveys some of the problems encountered, including the failure of the manipulator, malfunctioning of the 35-millimeter camera, and the tangling of the tether line. Nevertheless, the “future look[s] brighter” because of improved video pictures and the discovery of what was causing problems with the camera. Use of the submersible permitted detection of a “considerable quantity of aircraft pieces.” Danish scientists wanted to try to collect bottom samples using small nets and worried that aircraft pieces could interfere with that.

Owing to its improved performance, the Air Force gave a few more days to the Star III operation, through 28 August 1968, although it cancelled the last dive because of bad weather. “No parts of a weapon secondary were observed, and none of the weapon related parts have been recovered, nor do they show up in the photographs presently available.” During a briefing at Carl Walske’s office, there was speculation “that the missing [cylinder?] in view of its ballistic characteristics, may have come to rest beyond the observed concentration of the heavy debris.”

The report also included details on the final stages of the Crested Ice removal of contaminated material. The USNS Towles had left for South Carolina carrying 268 1,800-gallon tanks filled with contaminated liquid, 192 containers of debris, and 11 empty 25,000-gallon tanks. The USNS Marine Fiddler had arrived at Thule and was to be loaded with many more tanks filled with contaminated liquid and debris. According to the manager of AEC’s Savannah River operations, the “total amount of liquid snow to be returned and disposed of is 550,000 gallons,” at an estimated cost of $504,000.

Jan 22, 1968

Source: National Archives, Records Relating to Denmark, 1959-1974, box 5, Thule Crash -Internal Memos-Memcons- Conference Notes 1968

When Danish Foreign Minister Tabor announced the accident, he included language that Denmark’s no nuclear weapons policy included Greenland and “air space over Greenland.” Accordingly, “No nuclear weapons are stationed in Greenland.” U.S. authorities are “aware of Denmark’s nuclear policy, and we assume that there are no American flights over Greenland by aircraft carrying nuclear weapons.”

Given U.S. practice to keep nuclear armed bombers in the air, Tabor treated the accident as part of an “attempt to make an emergency landing” reflecting the “lack of landing facilities in the Arctic area.”

Meeting with Ambassador Torben Rønne to discuss a possible joint statement on the accident, Assistant Secretary of State John Leddy observed that the Danish statements about overflights and weapons storage “had come as a surprise to us.”  He did not explain why but Krag’s statement that there “can be no overflights” may have raised hackles because it raised questions about the 1951 defense agreement and the secret understanding with H.C. Hansen, which U.S. officials assumed legitimated nuclear overflights.[7] When Rønne said that his government had simply “restated” its policy, Leddy responded that Washington “did not want to go any further into this question” and that it would be “unwise to open … a discussion” of alert flight routes. Washington would not “challenge” Danish statements.

When Rønne met with Leddy the next day, he stated that the Department of Defense statement to the press on 22 January “pleased” his government. According to the statement, the B-52 carried nuclear weapons that were unarmed and that there was no danger of a nuclear detonation at the crash site. The Ambassador brought several questions from the Foreign Ministry, one of which “concerned the purposes of the various U.S. flights in the area,” specifically whether the plane that crashed “had any surveillance function, apart from its nuclear alert function.”

According to Rønne, that question had been a matter of “public discussion” in Denmark. Leddy said that “he could not say” but would investigate whether he could make information available. Apparently, the U.S. revealed nothing about the BMEWS monitoring task of the airborne alert B-52s at the time of the crash. It may have even been a secret at the State Department.

Meeting again with Leddy, Rønne emphasized the need for more information about the crash—at least a “small amount” of daily information. He suggested a “statement to the effect that there had been no B-52s in Greenland since the crash, or that those B-52s reportedly seen by Danes in Greenland had non-nuclear functions.” He later asked “if we couldn’t say they were radar planes or in some other way demonstrate that there were no atomic weapons connected with the operation of Thule.”

On 27 January, Assistant Secretary Leddy met with Ambassador Rønne and provided him with background concerning U.S. nuclear operations in Greenland. The State Department conveyed the same information to the Embassy in Denmark. This account sought to support U.S. claims that it had kept the Danes informed on key issues concerning storage and overflights through the discussions with Hansen in 1957 and Brun in 1964. Leddy also made a statement, which is excised, probably to the effect that the U.S. had no nuclear weapons in Greenland and that there were “[no] overflights of Greenland by U.S. strategic aircraft.” He emphasized “that in view of the sensitivity of military operations with nuclear weapons, the United States Government must continue to stand by its policy of neither confirming nor denying publicly the presence of nuclear weapons on its aircraft or bases anywhere in the world.”

Leddy proposed that the Danish government make a public statement that included this and other language: “U.S. operations in Greenland are the subject of regular consultation between the two Governments and are in accord with the 1951 Defense Agreement as well as their respective policies.” The Government of Denmark is “fully satisfied that the interests of the Danish people are being protected.”

The Danish Government had a public opinion problem that it needed to address. Dissatisfied by the U.S.’s proposed statement, which assumed Danish agreement with the U.S. interpretation of the 1951 agreement, Denmark’s government prepared an alternative, which Rønne discussed with Leddy. Corresponding to the essence of the briefing that Leddy had provided the day before, the statement read as follows: “The Danish Government which has had contacts with the US Government is in a position to confirm that in conformity with Danish atomic policy there are no nuclear weapons in Greenland and no overflights of Greenland by planes carrying such weapons are undertaken.”  Leddy responded that it was not possible for the U.S. government to be “be identified with the Danish statement.”

Rønne then met with Secretary of State Rusk, who also said that the U.S. could not associate itself with the Danish statement. One reason was that both U.S. and Danish security depend upon “US nuclear arrangements from which those countries receiving this protection cannot claim complete disassociation as if nuclear weapons did not exist.” The other was that the U.S. “had a serious problem of how to deal with events in one country so as not to set up a chain reaction with other countries throughout world that could impair the American nuclear deterrent.” That was the basis of the U.S. policy of neither confirming nor denying the presence of U.S. nuclear weapons, to which the U.S. had “adhered rigidly.” That policy made it possible for Denmark to say things that Washington could not or would not say.

As an alternative, Rusk proposed that Denmark make a short statement to this effect: “The Danish Government confirms that there are no nuclear weapons stored in Greenland and no overflights of Greenland with nuclear weapons.” If, however, the Danish government made such a public statement, the U.S. “would refuse to comment.”

Following Rusk’s suggestion, on 29 January 1968, the Danish government issued a statement confirming “that there are no nuclear weapons stored in Greenland and no overflights of Greenland with nuclear weapons.” According to the State Department’s message, the U.S. government “did not associate itself” with the statement; it advised recipients to follow the neither confirm nor deny approach.

Source: RG 59, Subject-Numeric Files, 1967-1969, box 1678

With the election of a new government in Denmark, a State Department intelligence report implied that the U.S. would have to change its approach to preserve its strategic access to Greenland.[8] The Bureau of Intelligence and Research (INR) estimated that the Government of Denmark would try to obtain assurances from Washington that it would no longer fly nuclear weapons over Greenland. “If the Danish Government fails to get such assurances, it and possibly also the Icelandic Government may have great difficulty in withstanding public pressure for forcing renegotiation of current base agreements to have explicit guarantees against such overflights and storage of nuclear weapons written into them.” Failure to secure U.S. assurances could lead to efforts by Denmark “to assume greater control over all US activities at Thule.”

Having returned from Denmark for consultations with the Foreign Minister of the recently elected government, Poul Hartling, Ambassador Rønne met with Under Secretary of State Nicholas Katzenbach. Rønne asked whether he could provide the new government with the same assurance that its predecessor had received: “to wit, the Danish Government confirms that there are no nuclear weapons stored in Greenland and no overflights of Greenland carrying nuclear weapons.” He also wanted to be able to state, for his Government’s “confidential information” that the U.S. “would not change this situation without first consulting” Denmark. Rønne added that he believed that the two governments “could explore in more relaxed way more formal assurances re nuclear question either in context of Greenland defense agreement or in diplomatic exchange.”

Katzenbach made an assurance about nuclear weapons, excised from this telegram, probably to the effect that the U.S. was not storing nuclear weapons or overflying Greenland with them. He added that it “was difficult for him to conceive circumstances where we would depart from this assurance without consulting unless circumstances were so extreme reasons for departure would be readily apparent.”

What Rønne suggested—future discussions to formalize U.S. assurances about Greenland’s non-nuclear status—became a necessity after the Danish parliament, the Folketing, passed a resolution on 8 February requiring “absolute [U.S.] guarantees that no nuclear weapons are stored in Greenland, and by ensuring in order that Greenland airspace remains a nuclear weapon-free zone, that Danish nuclear policy is upheld in all parts of the kingdom and Danish sovereignty respected.”

In the wake of the parliamentary resolution, David McKillop, chief of the Scandinavian Desk, anticipated that Rønne would make a request for talks on a formal understanding and that “some formal USG assurance is necessary in order to maintain our present defense capability in Greenland.” Recognizing that Denmark had a negotiating advantage because it held the “strongest cards,” McKillop advised that Washington could not take a “stance so rigid as to cause the Danes to question the desirability of retaining the 1951 Agreement on the Defense of Greenland.” He suggested that the U.S. could accept language providing for a “a nuclear free Greenland at present” but also permitting “the GOD to make a policy decision, in time of grave danger, to allow nuclear deployment and/or overflights.” McKillop noted that “we and the Danes realize that a situation might conceivably arise where there would be no time for consultations before initiating overflights or deployment.” A statement such as that made by Katzenbach to Rønne could cover that contingency.

As McKillop had predicted, Ambassador Rønne delivered a note on 26 February to Secretary of State Rusk requesting talks with the U.S. on a proposal to supplement the 1951 agreement with an understanding that “no nuclear weapons may under the agreement be stored in or introduced into Greenland including Greenland air space.” He made two points that he thought important: one was to reach an agreement “soonest” to end discussion of the nuclear problem in Denmark. The other was that his government was “flexible” about the procedure for reaching an understanding, whether through an “informal exchange of notes” or a supplementary protocol to the 1951 agreement.

When Rusk asked if Denmark had any issue with the “continued U.S. presence” at Thule or the possible need to introduce nuclear weapons into Greenland in “NATO alert situations,” Rønne replied that “continuation of Greenland defense agreement [was] not involved” but that Denmark’s no-nuclear policy “in peacetime” would apply to Greenland. The two governments could discuss the emergency introduction of nuclear weapons. Rusk closed the discussion with an “expression of appreciation for the fine Danish cooperation which had greatly facilitated handling of this regrettable crash.”

The declassification reviewers went overboard with this document, even excising text from the Parliamentary resolution and the Danish note which was published in its entirety in the State Department’s FRUS volume.

This Defense/State Department message informed the U.S. Embassy that it is “our firm policy to support our requirement for the BMEWS site at Thule, not only for the immediate future, but, in fact, until such time in the indefinite future that proven BMEWS replacement systems are deployed.” The “central location” of the BMEWS system at Thule between the sites in Alaska and the United Kingdom “provides primary coverage of the most logical approach route for Soviet ICBMs and covers a gap which exists between the other two sites except at relatively high altitude and extreme range.” Although new missile detection systems were under development, they would have limitations, making it necessary to prevent the “issues involving nuclear storage and overflights of Greenland [from] overshadow[ing] our need for the Thule BMEWS site,” which could extend beyond the early 1970s.

Discussion of the Danish proposal, including State Department-Defense Department consultations, began in the weeks after the meeting between Rønne and Rusk. During the talks, Rønne “tentatively” accepted the U.S. view that the agreement would be secret as well as U.S. arguments that instead of an “absolute ban” “future nuclear overflights and storage in Greenland should be subject to consultation” between the two governments.

The State Department proposed the following language: an assurance that “notwithstanding the provisions of the 1951 agreement” the U.S. would not “store nuclear weapons in Greenland or overfly Greenland” with nuclear-armed aircraft. But the U.S. wanted Denmark to recognize that “in circumstances of extreme emergency” advance consultation could be difficult but that the U.S. would “make every effort” to do so.

After Rønne objected to the paragraph about “extreme emergency,” the State Department walked it back, omitting it from the text. As McKillop had suggested earlier in the discussions, Leddy proposed a U.S. “spoken” comment about the possibility of a “grave and sudden threat that did not allow time to obtain” Denmark’s agreement. Rusk approved the new formulation of the note and Leddy’s proposal for a supplementary statement.

At a meeting with Ambassador Rønne on 10 May, Leddy provided a draft U.S. text but said that when the two countries exchanged notes he would “reiterate possible requirement for US overflights under circumstances of a grave and sudden threat that does not allow time to obtain agreement of Danish Government.” When Rønne observed that the proposed statement would make the agreement “less than binding,” Leddy replied that the “written agreement would be [the] governing instrument” and that as with any U.S. government agreement “we would abide by it to full extent of our ability to do so.” When Rønne asked why the agreement had to be secret, Leddy replied that it “embodied a specific limitation on [the] deployment and movement of nuclear weapons.”

This may be the one of the few memos involving the Greenland nuclear issue that crossed President Johnson’s desk. Rostow explained the state of play of the talks with Denmark over the proposed note, which had Rusk’s approval “subject to your concurrence.” Rostow informed Johnson that Leddy had made an oral statement “that there may be a need for nuclear overflight under conditions of a grave and sudden threat that did not allow time to obtain the agreement of the Danish government.” Rostow further noted that the agreement avoided “a full scale renegotiation of the 1951 agreement which covers our air base and radar installations in Greenland.”

The draft agreement went through more changes, with the Danes proposing to remove the language “notwithstanding the provisions of the 1951 agreement” because they saw it as an implicit justification for the U.S. interpretation that the agreement validated previous U.S. actions on nuclear overflights and storage.[9] Instead, they proposed more neutral language that State Department negotiators accepted.

As the talks closed, Leddy briefed Under Secretary Katzenbach on their outcome. Besides giving the U.S. freedom of action during a defense emergency, the State Department had protected the “neither confirm nor deny” policy because Copenhagen “agreed to drop its request for any U.S. participation in or endorsement of a public statement concerning nuclear weapons in Greenland.”

As Hans Kristensen has noted, there was an important “hole” in the agreement. Unlike the 26 February proposal, it did not include language prohibiting the “introduction” of nuclear weapons into Greenland, which would have been broad enough to exclude visits to ports by U.S. ships carrying nuclear weapons.

On 31 May 1968, Leddy and Rønne exchanged notes that, the State Department informed the U.S. Embassy, “would form an integral part of 1951 Greenland Agreement.” According to Rønne, the Danish government would make a statement that the State Department would find “acceptable and that USG interests, as expressed during recent negotiations, had been taken into account.” The same day, the Danish Foreign Ministry issued a statement that concluded with this language: “The result of the discussions in Washington creates harmony between the Defense Agreement of 1951 and Danish atomic policy and therewith assurance under international law, that this policy is respected in Greenland.” With some limitations, the Government of Denmark had successfully integrated Greenland into its no-nuclear policy.