35+ Years of Freedom of Information Action

Alerts, Crises, and DEFCONs

USS Forrestal

USS Forrestal, Sunday, 11 November 1956 (Suez Crisis), steaming in the Atlantic enroute to the Mediterranean to join the Sixth Fleet, in company with Task Force 26. The USS Franklin D. Roosevelt (CVA-42) can be seen in the background. [Source: NavSource Online]

Published: Mar 17, 2021
Updated: May 26, 2021
Briefing Book #750

Edited by William Burr

For more information, contact:
202-994-7000 or nsarchiv@gwu.edu

U.S. Shows of Force Became Routine During International Crises

Canadians Worried that U.S. Nuclear Armed Exercise Could Prompt Soviet Attack in 1959 Berlin Crisis

Part I: From the 1948 Berlin Crisis to the First DEFCON

New: 1966 RAND Report Shows U.S. Was "Fairly Close" to Nuclear Use against China


Washington D.C., May 26, 2021 – “The United States came fairly close to using tactical nuclear weapons” during the Taiwan Strait Crisis of 1958, according to a top-secret 1966 RAND summary report posted today for the first time by the National Security Archive.  Washington contemplated this extreme response to anticipated Chinese aggression “despite opposition to its policy by most of its allies and many in the United States,” the report notes.

Furthermore, even though President Dwight Eisenhower had insisted to his commanders that conventional armaments should be used first, the study found that the president’s written and spoken comments to other officials “left little doubt ... that he was prepared to use nuclear weapons.”

Today’s update adds an important chapter to the story of U.S. reactions to military and political crises during the early Cold War.  The RAND summary was prepared by defense analyst Morton H. Halperin at the same time he prepared a larger, highly classified, 691-page report on the topic highlighted recently by The New York Times.  The National Security Archive obtained Halperin’s declassified summary through the Freedom of Information Act.

To provide direct perspective on the report, the Archive includes in this updated posting a Q&A about its current relevance and significance with the author, Morton Halperin.



Washington D.C., March 17, 2021 – During the 1950s and early 1960s, a remarkable number of crises arose during which U.S. leaders made threats, authorized nuclear weapons for use, and put strategic forces in a higher state of readiness, manifesting an almost reflexive reliance on displays of military force, according to a National Security Archive study posted today of declassified records, many published for the first time, on the use of alerts and the Defense Condition (DEFCON) system.   

From Berlin in 1948 to Suez and Taiwan in the 1950s to Cuba in 1962, and Lebanon and Korea in the 1970s, the United States almost routinely put its armed forces, including the Strategic Air Command (SAC), on alert, ostensibly to deter adversaries or to support diplomatic objectives.  At times, the U.S. posture struck a nerve among its allies.  For example, State Department memos from 1959 report that Canadian officials were growing anxious that nuclear-armed SAC overflights might trigger an East-West war.   

Today’s posting, the first of two parts on the subject, features numerous documents that are being published for the first time – mainly declassified official internal histories – and that cover a variety of important strategic and procedural developments, including the creation of the DEFCON system in 1959.  It also documents the first use of the DEFCON system after the Paris Summit collapsed in May 1960 over the U-2 crisis.

* * * * *

Alerts, Crises, and DEFCONs

By William Burr

When the U.S. Marines landed on the beaches near Beirut in July 1958, during the Lebanon crisis, the Eisenhower administration wanted to ensure that the Soviet Union stayed out of the Middle East. To deter Moscow from any thought of intervention, at the president’s request, the Strategic Air Command put its forces in the U.S. and overseas on alert. According to documents published today by the National Security Archive, by 18 July 1132 SAC bombers, mainly B-47s, were in combat configuration. Of those, 405 were on a high alert “full show of force” posture, with nuclear weapons loaded. SAC maintained that posture for five days. The alert included bombers deployed on rotation in Spain, Morocco, and the United Kingdom under the “Reflex” program. SAC forces stayed on alert through the end of the month. It was the largest SAC alert before the DEFCON 2 of the Cuban Missile Crisis.

Today’s posting suggests how a near-reflexive reliance on shows of force during foreign policy crises became a matter of course for Washington during the early years of the Cold War. This became a continuing pattern. When diplomatic and military crises broke out and Washington saw threats to its interests in Europe, Asia, the Middle East, or elsewhere, or was at loggerheads with Beijing or Moscow, U.S. presidents and their advisers often put armed forces, the U.S. Navy or SAC or both, on alert, often on a war footing, to deter adversaries with devastating threats. The crises stretched around the world, from Berlin in 1948 to Lebanon and Taiwan in 1958 and to Korea in 1968 and 1976 In those crises and others, Washington alerted strategic forces as a show of force to support diplomatic objectives and in the event a crisis turned into military confrontation.

In today’s posting, the first of two parts on the subject, the National Security Archive publishes documents – mainly declassified official histories, many of the records for the first time – on alerts that took place from 1948 to 1958, from the Berlin Crisis of 1948 to the Taiwan Strait Crisis of 1958. In addition, the posting documents the creation of the Defense Condition [DEFCON] system – recorded in a 1959 Joint Chiefs of Staff memorandum – that created it and materials relating to the first DEFCON in May 1960 at the time of the breakdown of the Paris Summit.

At the time of the first crisis documented in today’s publication, during 1948-1949 over Berlin, the Strategic Air Command had a nuclear mission, but it did not have access to nuclear weapons. The Atomic Energy Commission had direct control of the weapons and any change in custody would require a presidential decision. Harry Truman, who saw nuclear weapons as terror weapons, rejected military custody even after the Berlin Crisis had begun.[1] During the Crisis, SAC bombers sent to Western Europe on an emergency basis were only equipped with conventional explosives. The few “Silver Plated” nuclear-capable B-29s remained in the United States.

After the Korean War broke out Truman’s opposition to military control slightly relaxed, and he began to allow deployments of atomic weapons components overseas and on aircraft carriers. That included bomb components shipped to the Western Pacific as part of the U.S. threat posture during the war. [2] During the Eisenhower administration, however, the Air Force, the Army, and the Navy began to have routine access to complete nuclear weapons.[3] Thus, during subsequent Cold War crises, U.S. Navy’s aircraft carriers steaming to their destinations in the Western Pacific or the Eastern Mediterranean carried nuclear weapons while bombs could be uploaded on SAC bombers for alert actions.[4] The most dramatic example was the Cuban Missile Crisis, where SAC’s DEFCON 2 posture put hundreds and hundreds of nuclear-armed bombers and ICBMs ready for rapid strikes on targets assigned by war planners.[5]

During the 1950s and early 1960s, there were a remarkable number of crises during which U.S. leaders made threats, authorized nuclear weapons for use, and put strategic forces in a higher state of readiness. While the Soviets also made threats, e.g., Suez, in 1956, the U.S. threat posture was comparatively overwhelming. In addition to Suez, other crises included the Korean War, Indochina in 1954, the Taiwan Strait in 1954-55, Lebanon and Taiwan in 1958, and Cuba in 1962.

President Eisenhower who presided during most of these crises was not bloodthirsty but believed that U.S. nuclear superiority and threat-making were advantageous to protecting national interests. Eisenhower initially regarded nuclear weapons as first-resort munitions – for all intents and purposes the same as conventional weapons – especially in a U.S.-Soviet war. Yet by the time of the second Taiwan Strait Crisis, he was rethinking his position on nuclear use and ordered military leaders to use conventional weapons first in any clash with Chinese forces. [6]

The Taiwan Strait Crisis notwithstanding, Eisenhower relied on “massive retaliation” and general war threats in the event of an actual military clash with Beijing or Moscow. During the 1958-1959 Berlin Crisis, he expected that the U.S. would initiate general nuclear war if there was a military conflict with the Soviets over allied access to West Berlin. For him this was the ultimate and most persuasive deterrent threat because he did not expect war to break out. Although some civilian strategists had been calling for flexible response and reliance on conventional non-nuclear options as a more credible deterrent than all-out nuclear war, Eisenhower rejected that altogether not least because it would break the limits on federal spending that he believed were essential.[7]

At the close of the 1950s, the Defense Department made a major change in its responses to significant crises. As in the past, the CINCs of specified commands, such as SAC, EUCOM, and PACOM would alert forces either on their own or in response to directives. Each command would respond to orders with its own set of procedures, but the Joint Chiefs wanted more certainty as to what that would mean. Thus, with the inauguration of the DEFCON system in 1959, the Joint Chiefs wanted assurance as to what a given level of alert for a given command would involve. With a directive that it issued in August 1959, the Joint Chiefs defined what the DEFCONs would mean and directed each of the commands to prepare reports on how they would respond to the situation, subject to further review by the high command.

This survey of the record of alerts and crises during the years before 1960 is by no means complete or comprehensive. It would be worth taking account of such events as Korea in 1950, the Indochina crisis in 1954, and the Taiwan Strait in 1954-5. The last two events were not the subjects of official histories while official histories of SAC and Korea in 1950 are not yet declassified. Moreover, accessing the declassified archival record on military operations during those crises is not possible during the pandemic. Nevertheless, the record that is at hand provides useful reminders of instances when the U.S. government used threats of force, directly or otherwise, to try to steer world events in ways that policymakers believed were compatible with national interests.

Looking at those events makes it worth assessing how adversaries saw those moves and how they affected their own military policies. Also important to consider is the impact of shows of alerts and shows of force on the reputation of the United States, whether enhancing or detracting. Taking such matters into account can inform conclusions as to whether those actions contributed to the United States’ long-term interests.[8]


The documents

Morton Halperin Looks Back on His Taiwan Crisis Study

Halperin responded to questions from the National Security Archive in connection with his January 1966 RAND paper on the Taiwan Strait Crisis, May 26, 2021


National Security Archive: Does this study remain relevant to the current tensions over Taiwan?

MH: The study is relevant to the current tensions over Taiwan since the ambiguity in the American commitment to the security of Taiwan continues to this day. In 1958 the United States felt it had a choice as to whether to help Taiwan defend Quemoy. Eisenhower made the decision to do so without consulting Congress or the public and appeared to be ready to use nuclear weapons. The offshore islands all remain under the control of Taiwan and the PRC might well begin its offensive by seizing the islands.

National Security Archive: When you wrote this study, what were your impressions of U.S. nuclear war plans for conflicts with China? How dangerous did you think they were?

MH: It is worth noting that the Air Force historian arranged for me to be treated as if I was an Air Force researcher and not a contractor, which gave me unusual access to internal Air Force and JCS documents both in the Pentagon and at CINCPAC in Hawaii. I also visited Quemoy and got to see for myself how close it is to the mainland.

In my view, the most illuminating part of the unredacted study is its description of the role that nuclear weapons played in the Eisenhower Administration’s military posture. As the documents I cite and quote make clear, the Administration labeled nuclear weapons as “conventional” weapons, and what we know as “conventional” weapons were called “obsolete iron bombs.” U.S. military forces including those engaged in the Taiwan Straits were equipped and trained only to fight a nuclear war and had nuclear weapons on board and ready. As the Joint Chiefs kept reminding the President, they could only fight for a few hours without using nuclear weapons.

The JCS told the President that if the PRC launched an invasion of Quemoy, the US needed to intervene immediately or the island, very close to the mainland, would fall. Eisenhower authorized the military to resist an invasion but not to use nuclear weapons without his permission. They reminded him again that once they started fighting they would quickly run out of “obsolete iron bombs” and need to use nuclear weapons.

Only the decision of the PRC to curtail the bombardment of the islands and not to invade prevented a nuclear war. We still are not certain why Mao made that decision.

Thus, our nuclear doctrine and war plans were for early mandatory first use. The posture in my view was extraordinarily dangerous. It is critical to understand that these war plans had been fundamentally changed by the time I did the research.

President Kennedy and Secretary of Defense Robert McNamara had completely altered the policy starting with the labels. Nuclear weapons were once again called “nuclear weapons.” Non-nuclear weapons were again called “conventional” weapons. The armed forces were again equipped to fight extended conventional wars. While not ruling out first use, the doctrine called for confronting military threats with the least force necessary to prevail.

National Security Archive:  Is there any valid reason for keeping your study classified so many decades later? Or is this an abuse of secrecy?

MH: There was no valid reason to keep any of the study classified when I wrote it and certainly not decades later. RAND as a government contractor has no obligation to produce unclassified versions of the classified studies it does for the government. At my request it did ask the government to do a declassification review which led to the release of all of the study save for the portions dealing with nuclear weapons. RAND was in no position to challenge the decision to keep the nuclear portions secret.

Morton Halperin

Morton Halperin has had a long career in and out of government since the 1960s, when he was a Deputy Assistant Secretary of Defense for International Security Affairs, 1966-1969, and a member of the National Security Council Staff during 1969, the first year of the Nixon administration. During that year, Henry Kissinger and Alexander Haig had him wiretapped on suspicion of leaking and he resigned when Kissinger made it untenable for him to remain at the NSC. Once the wiretaps were disclosed he sued but dropped the suit in 1992 after Kissinger apologized. After working at the Brookings Institution, he became Director of the National ACLU’s Washington, D.C. office, 1975-1992. In that capacity, Halperin was an original sponsor of the National Security Archive and served on the Archive's board through 1992. During the Clinton administration, he worked in a variety of roles at the NSC, the Defense Department, and the State Department, where he was Director of the Policy Planning Staff. Since 2002 he has played major roles at the Open Society Foundations, currently as a Senior Adviser to the Foundations. He also serves as Chair Emeritus of the Board of J Street.



[1]. For the emerging nuclear taboo during the Truman years, see Nina Tannenwald, The Nuclear Taboo: The United States and Non-Use of Nuclear Weapons since 1945 (New York: Cambridge University Press, 2007), 73-114.

[2]. Roger Dingman, “Atomic Diplomacy During the Korean War,” International Security 13 (1988/89): 50-91.

[3]. David Alan Rosenberg, “The Origins of Overkill: Nuclear Weapons and American Strategy, 1945-1960,” International Security 7 (1983): 27-28.

[4]. For a useful catalog of the range of naval activities, from show of force to humanitarian missions, see Adam B. Siegel, Use of Naval Forces in the Post-War Era: U.S. Navy and U.S. Marine Corps Crisis Response Activity, 1946-1990, Naval History and Heritage Command, n.d.               

[5]. For the military and organizational basis of deterrence at the outset, see Rosenberg, “Origins of Overkill.”  For more on war planning and the mentality of the planners, see NAPSNET [Nautilus Peace and Security Network] Special Report by Lynn Eden, “U.S. Planning for Pandemics and Large-Scale Nuclear War,” 25 November 2020, revised version scheduled for publication in the Journal for Peace and Nuclear Disarmament, March 2021.

[6]. Rosenberg, “Origins of Overkill,” 28; Marc Trachtenberg, A Constructed Peace: The Making of the European Settlement, 1945-1963 (Princeton, Princeton University Press, 1999). 185; Tannenwald, The Nuclear Taboo, 165-181.

[7]. David Allen Rosenberg, “Constraining Overkill: Contending Approaches to Nuclear Strategy, 1955-1965,”  Paper Presented at “‘More Bang for the Buck’: U.S. Nuclear Strategy and Missile Development 1945-1965,” Colloquium  on Contemporary History January 12, 1994 No. 9.

[8]. The impact of the Taiwan Strait Crisis of the 1955 on Chinese decisions to acquire a nuclear capability is a case in point. See John Lewis and Xue Litai, China Builds the Bomb (Stanford: Stanford University Press, 1988).]

[9]. Melvyn P. Leffler, A Preponderance of Power: National Security, the Truman Administration, and the Cold War (Stanford: Stanford University Press, 1992), 217-218.

[10]. William Stivers, “The Incomplete Blockade: Soviet Zone Supply of West Berlin, 1948–49,” Diplomatic History 21 (1997): 569-602.

[11]. Leonard Wainstein et al., Institute for Defense Analyses, Evolution of U.S. Strategic Command and Control and Warning 1945-1972 (Arlington, 1975), pages 31 (for atomic weapons deployments in 1950), and 75 (for the non-nuclear status of the SAC aircraft in Europe during the Berlin Crisis). See also Ken Young, The American Bomb in Britain: U.S. Air Forces Strategic Presence, 1945-1964 (Manchester: Manchester University Press, 2016), 35-44.

[12]. For background and context, see Richard Immerman, John Foster Dulles: Piety, Pragmatism, and Power in US Foreign Policy (Wilmington, DE: Scholarly Resources, 1999). 149-157, and William I. Hitchcock The Age of Eisenhower: America and the World in the 1950s (New York: Simon & Schuster, 2018), 306-340.  For U.S. pressure and military activity in early November, see also Cole C. Kingseed’s major account, Eisenhower and the Suez Crisis of 1956 (Baton Rouge: Louisiana State University Press, 1995), 121-123.

[13]. Kenneth W. Condit History of the Joint Chiefs of Staff Volume VI: The Joint Chiefs of Staff and National Policy 1955-1956 (Washington, D.C.: Office of Joint History. Office of the Chairman of the Joint Chiefs of Staff 1998), 189; Kingseed, Eisenhower and the Suez Crisis, 123.

[14]. Kenneth W. Condit, History of the Joint Chiefs of Staff Volume VI, 191; “1,000 B-47s in Air at Peak of Crises,” New York Times, 19 December 1956. Brian Rogers and Robert S. Hopkins III are preparing a study, Klaxon!, on SAC Cold War alerts, which will includes a detailed account of this alert among others.

[16]. For background, see memo of conference with the President, 15 July 1958, 11:25 a.m., FRUS, 1958-1960, document 140;  Douglas Little, American Orientalism: The United States and the Middle East since 1945 (Chapel Hill, NC: University of North Carolina Press, 2008), 134-135; Immerman, John Foster Dulles, 165-166, and Hitchcock, The Age of Eisenhower, 399-400.

[17] . For important studies, see Gordon H. Chang and He Di, “The Absence of War in the U.S.-China Confrontation: Contingency, Luck, Deterrence?” American Historical Review (1993): 1500-1524, and Chang, Friends and Enemies: The United States, China, and the Soviet Union, 1948-1972 (Stanford: Stanford University Press, 1990), 121-140.

[18]. For U.S. policy during the 1958 crisis, see Immerman, John Foster Dulles, 178-185, as well as Gordon H. Chang, Friends and Enemies, 86-201. For a granular study of day-to-day developments, decisions, and operations, see Morton H. Halperin, The 1958 Taiwan Strait Crisis: A Documented History, Rand Corporation Research Memorandum RM-4900-ISA, December 1966, at Daniel Ellsberg Web site.  For Chinese policy, see Nancy Bernkoff Tucker, Strait Talk: United States-Taiwan Relations and the Crisis with China (Cambridge, MA: Harvard University Press, 2009), 16-17.

[19]. For more on military planning and military moves before the crisis broke out, see Halperin, The 1958 Taiwan Strait Crisis, 48-60.

[20]. See also ibid, at 126-137

[21]. For more on Eisenhower’s decisions on 25 August, see Halperin, The 1958 Taiwan Strait Crisis, at pages 112-126.  Eisenhower would make related points in discussion with British Foreign Secretary Selwyn Lloyd later in September 1958.  See Tannenwald, The Nuclear Taboo, 182-185 and 188-189.  For Eisenhower’s restraint during the crisis, see Hitchcock, The Age of Eisenhower, 400-404.

[22]. Immerman, John Foster Dulles, 182. For Eisenhower’s decisions on 6 September, see Halperin, The 1958 Taiwan Strait Crisis, at 285-287.  For debates on nuclear weapons use among the Joint Chiefs and other top advisers, see ibid., at 256-275. 

[23]. See Allen S. Whiting, “Quemoy 1958: Mao’s Miscalculation,” China Quarterly (1975): 63-70, cited in Tucker, Strait Talk, at 287.

[24] . Chen Jian, Mao’s China and the Cold War (Chapel Hill, University of North Carolina Press, 2001), Chapter VII, “Beijing and the Taiwan Strait Crisis of 1958,” 163-204.

[25]. For an overview, see Immerman, John Foster Dulles, 86-96. Trachtenberg, A Constructed Peace, remains an important study, see 251-282. See also William Burr, “Avoiding the Slippery Slope: The Eisenhower Administration and the Berlin Crisis, November 1958–January 1959,” Diplomatic History 18 (1994): 177-205.  During the late 1960s, Arthur Kogan, a Department of State historian, prepared a multi-part history of the Berlin Crisis through September 1961. While limited to State Department sources, it remains a useful account.  For the Eisenhower period, see Historical Studies Division, Historical Office, Bureau of Public Affairs, U.S. Department of State, Crisis Over Berlin, American Policy Concerning the Soviet Threats to Berlin, November 1958-December 1962 (Unpublished Top Secret Research Project No. 614-A, October 1966), Part I, Part II, Part III, and Part IV.

[26]. David Allen Rosenberg, “Constraining Overkill: Contending Approaches to Nuclear Strategy, 1955-1965.

[27]. HEAD START II, involved 1384 sorties during the March-June 1959 period, very close to the original objective of 1,400. According to the SAC historians, “the overall performance [of the units involved] was outstanding.” See Headquarters Strategic Air Command, The SAC Alert Program, 1955-1959, n.d., 108-118, copy on DNSA.

[28]. In early 1961, the CIA prepared a paper on “Clandestine Action in Support of U.S. Berlin Policy,” 23 March 1961, which can be found in the CIA’s “Berlin Wall” collection.  The paper, however, is displayed incorrectly so the first page is at the end of the scan.

[29]. For the early phases of the new DEFCON system, see Scott D. Sagan, The Limits of Safety: Organizations, Accidents, and Nuclear Weapons (Princeton: Princeton University Press, 1993)

[30]. For Gates’ decision at Paris and Eisenhower’s approval, see Robert J. Watson, History of the Office of the Secretary of Defense Volume IV: Into the Missile Age, 1956-1960 (Washington, D.C.: Historical Office, Office of the Secretary of Defense, 1997), 722-723.