During an impromptu April 18 press conference, President George W. Bush was asked if his assertion that “all options are on the table” regarding Iran included the possibility of a nuclear strike. Bush reiterated, “All options are on the table. We want to solve this issue diplomatically, and we’re working hard to do so.” In no uncertain words, the president of the United States directly threatened Iran with a preemptive nuclear strike. It is hard to read his reply in any other way.
It was not the first time that a U.S. president has threatened to use nuclear weapons. In previous instances, U.S. officials have generally made such threats during periods of crisis. Some were direct threats, others were ambiguous, and some implied that nuclear plans were merely being considered. The threats had mixed effects. In some cases they clearly deterred an adversary; in others they seem to have had little or no effect. In at least one situation, a nuclear threat appears to have persuaded a nation to build its own nuclear arsenal.
Bush’s statements regarding Iran are particularly reminiscent of a diplomatic strategy employed by President Richard Nixon known as the “madman theory.”  On the eve of a massive mining and bombing campaign against North Vietnam in October 1969, Nixon ordered that nuclear forces be placed on a higher state of alert in order to pressure the Soviets and the North Vietnamese into making diplomatic concessions that might eventually bring an end to the war.  The madman theory, or, as Nixon and his chief of staff Bob Haldeman described it, “the principle of the threat of excessive force,” was at the center of this strategy. “Nixon was convinced that his power would be enhanced if his opponents thought he might use excessive force, even nuclear force. That, coupled with his reputation for ruthlessness, he believed, would suggest that he was dangerously unpredictable,” according to analysts William Burr and Jeffrey Kimball.  As part of the strategy, underlings would transmit information to foreign officials saying that Nixon might be unstable or unpredictable and that unless concessions were made he might order the use of military force or even nuclear weapons. The entire effort was conducted in extreme secrecy with only a few U.S. officials even aware of it.
Beginning on October 13, 1969, the U.S. Strategic Air Command (SAC) placed 144 B-52 bombers, 32 B-58 nuclear bombers, and 189 KC-135 tankers on ground alert. This number, it was assumed, would be “discernible to the Soviets but not threatening in themselves” in the words of Gen. Earle G. Wheeler, chairman of the Joint Chiefs of Staff. Several SAC bombers, loaded with four or more nuclear bombs, flew continuously “over the frozen terrain of the Arctic” in late October, according to Burr and Kimball.  The readiness level would continue until there was an indication that the Soviets had taken notice.
In the end, all of this muscle flexing had little effect. There is no documentary evidence that Moscow ever expressed concern. The failure of the show of force did not lessen the validity of the madman theory in Nixon’s mind, Burr and Kimball believe. He “continued to believe that threats of force, military signaling, and alerts intimating nuclear threats were valid and necessary tools of diplomacy.” 
From various comments that Bush has made about Iran, it could be argued that he has chosen at times to practice a version of the madman theory.  One difference between the two presidents is that Bush is sending the signals via public statements and selective leaks, though back channels also may be in use. There is no indication that any special military measures were taken to back up Bush’s rhetoric, though there are no doubt contingency plans. Regardless, Bush joins a long list of U.S. officials, including his father, who have drawn the nuclear sword in an effort to influence international relations.
On the Korean Peninsula. One of the first instances of a U.S. threat of nuclear use came just five years after the Hiroshima and Nagasaki bombings. With the United States mired in the Korean War, in November 1950 a reporter asked President Harry S. Truman whether U.N. forces might cross the Yalu River into Manchuria. Truman responded, “We will take whatever steps are necessary to meet the military situation, just as we always have.” Asked whether that included using atomic bombs, Truman responded: “That includes every weapon we have.” A few minutes after the press conference ended, the lead of the United Press wire story read, “President Truman said today that the United States has under consideration use of the atomic bomb in connection with the war in Korea.” 
Nearly three years later, Truman’s successor, President Dwight Eisenhower, also wielded the threat of U.S. nuclear use. In May 1953, Eisenhower authorized an expanded Korean bombing campaign, prompting the North Koreans and Chinese to respond by increased ground action. As part of the heightened military activity, the Joint Chiefs presented six different scenarios for ending the war, “most envisioning the possible use of atomic weapons,” according to an official Pentagon history. “After the NSC reached a seeming consensus on May 20 to employ atomic weapons both strategically and tactically–that is within and outside the Korean Peninsula–the administration communicated its resolve to the Chinese and North Koreans. . . . Both Eisenhower and [Secretary of State John Foster] Dulles believed the message had the desired effect” of ending the war, the history reads. 
In what later became known as the “Tree-Trimming Incident,” U.S. forces in Korea again threatened the use of nuclear weapons when they were placed on DEFCON 3 on August 19, 1976. The alert, which was ordered in response to a fatal skirmish between U.S. and North Korean border guards over U.S. attempts to trim a tree in the demilitarized zone, involved deployment of nuclear and other forces in operations that signaled preparations for an attack on North Korea.  The U.S. display of force included nuclear-capable B-52 bombers flying “from Guam ominously north up the Yellow Sea on a vector directly to . . . Pyongyang,” noted Maj. Gen. John K. Singlaub in his book, Hazardous Duty.  North Korea did not interfere with the tree trimming again, so the flexible U.S. options appeared to work.
Most recently, during the 1994 North Korean nuclear crisis, the United States nearly launched a conventional strike against the North’s nuclear production facilities. Although nuclear threats were not reported to have been part of the effort, U.S. Strategic Command (Stratcom) did apparently study the nuclear option in 1995. And during 1997 congressional hearings, Gen. Eugene Habiger, commander of Stratcom, confirmed that indeed the United States had threatened the North with nuclear weapons during the crisis. Asked what “sort of deterrence” he thought U.S. nuclear weapons played in preventing WMD from being used by rogue states, Habiger responded, “In my view, sir, it plays a very large role. . . .[The threat of U.S. nuclear use] was passed to the North Koreans back in 1995, when the North Koreans were not coming off their reactor approach they were taking.”  Habiger subsequently explained that the message passed on to North Korea had been explicit. 
Regarding Taiwan. After the founding of the People’s Republic of China on October 1, 1949, Chinese Nationalists in Taiwan retained control of the offshore islands of Jinmen (Quemoy) and Mazu (Matsu) to harass the Chinese Communists.  On September 3, 1954, Chinese coastal batteries began shelling Jinmen, where more than 50,000 Nationalist soldiers were stationed. The crisis intensified significantly in January 1955, forcing Eisenhower to consider whether the United States would allow the loss of the islands, thus possibly undermining its commitment to Taiwan.
In the midst of the crisis, during a March 8 nationally televised speech, Secretary Dulles said that the administration considered atomic weapons “interchangeable with the conventional weapons” in the arsenal. Over the next week, U.S. officials, including Eisenhower and Vice President Richard Nixon, made numerous public statements about employing tactical nuclear weapons if war broke out. The statements were meant to prepare Americans for nuclear warfare and in the hope of deterring the Chinese from attacking. Along with the verbal threats, Gen. Curtis E. LeMay, commander of SAC, made extensive military preparations, deploying B-36s bombers to Guam and selecting their targets in China.
The crisis broke when Chinese Premier Zhou Enlai announced on April 23 that China was willing to negotiate with the United States to reduce tensions over Taiwan. But the confrontation had serious repercussions for the global nuclear balance; Eisenhower’s nuclear saber rattling convinced Chairman Mao Zedong that China needed its own nuclear weapons. In January 1955, less than a year after the U.S. nuclear threat, China formally made a decision to develop the Bomb.
U.S. officials threatened nuclear use during a similar crisis in 1958. When China moved forces into the Fukien (Fujian) province opposite Taiwan that summer, U.S. officials prepared contingency plans and cautioned the Chinese not to threaten the peace in the area. On August 23, Chinese-artillery batteries unleashed a ferocious barrage against Quemoy. While the strikes continued intermittently for weeks, the U.S. prepared a military response, including making a squadron of Guam-based B-47 bombers available for nuclear strikes against the mainland.  Other plans involving nuclear weapons were discussed and made ready. The crisis dragged on for two months until China inexplicably stopped the barrages. The official Defense Department historian labeled the threat of nuclear use as “important” in resolving the standoff, adding, “Indeed on no other occasion during Eisenhower’s second term was [nuclear weapons] use so seriously considered.” 
Desert threat. The United States has considered or threatened the use of nuclear weapons on several other occasions: In response to the 1948 blockade of Berlin; in support of French forces in the northern Vietnamese town of Dien Bien Phu in 1954; in response to rioting that threatened the Lebanese government in 1958; during the Cuban Missile Crisis of 1962; in order to counter Soviet saber rattling after the breakdown of a U.N. sanctioned truce in Israel in 1973; and as an option to penetrate Libya’s Tarhuna underground chemical weapons facility in 1996.  But perhaps the most well-communicated U.S. nuclear threat was made prior to the U.S. intervention during the 1991 Gulf War.
During Operation Desert Storm in January 1991, the George H. W. Bush administration issued a formal threat of retaliation in response to chemical or biological weapons use and also against Iraqi support of any kind of terrorist actions. During a meeting with Iraqi Foreign Minister Tariq Aziz on January 9, 1991, Secretary of State James Baker handed Aziz a letter from Bush and warned that, if “God forbid . . . chemical or biological weapons are used against our forces–the American people would demand revenge.”
“This is not a threat,” Baker continued, “but a pledge that if there is any use of such weapons, our objective would not be only the liberation of Kuwait, but also the toppling of the present regime.”  Baker later explained that he “purposely left the impression that the use of chemical or biological agents by Iraq would invite tactical nuclear retaliation.”  The letter listed three “sorts” of “unconscionable actions” by Iraq that would demand the “strongest possible response”: use of chemical or biological weapons; support of any kind of terrorist action; and the destruction of Kuwait’s oilfields and installations. 
Bush had secretly decided that U.S. forces would not use nuclear weapons, but Baker and other former officials from the George H. W. Bush administration have since revealed that they used Arab intermediaries and even Japanese diplomats to convey an explicit nuclear threat to Saddam Hussein.  Although the third “unconscionable action”–destruction of the Kuwaiti oilfields–was not deterred, Baker concluded, “We do not really know whether [the nuclear threat] was the reason” that Iraq did not use chemical or biological weapons. “My own view is that the calculated ambiguity regarding how we might respond has to be part of the reason.” 
If so, that lesson was not lost elsewhere in the world. After the 1991 Gulf War, the former deputy defense minister of India concluded, “Never negotiate with the United States unless you have a nuclear weapon.”
1. The theory was first made public by Nixon’s chief of staff, H. R. “Bob” Haldeman. “I call it the Madman Theory, Bob. I want the North Vietnamese to believe I’ve reached the point where I might do anything to stop the war. We’ll just slip the word to them that, ‘for God’s sake, you know Nixon is obsessed about communism. We can’t restrain him when he’s angry–and he has his hand on the nuclear button’–and Ho Chi Minh himself will be in Paris in two days begging for peace.” H. R. Haldeman, The Ends of Power (New York: Times Books, 1978).
2. William Burr and Jeffrey Kimball, “Nixon’s Nuclear Ploy,” Bulletin of the Atomic Scientists, January/February 2003, pp. 28-37, 72-73.
3. Ibid., p. 31.
4. Ibid., p. 72.
5. Ibid., p. 73.
6. Jeffrey Kimball, “Is Bush Trying Out the Madman Theory?” History News Network, February 28, 2005.
7. David McCullough, Truman (New York: Simon and Schuster, 1992), pp. 821-822.
8. Richard M. Leighton, Strategy, Money, and the New Look 1953-1956, vol. III of the History of the Office of the Secretary of Defense (Washington, D.C.: Historical Office, Office of the Secretary of Defense, 2001), p. 2. The same message was conveyed to Soviet Foreign Minister V. M. Molotov on June 3. The armistice was signed on June 27, 1953.
9. Richard A. Mobley, “Revisiting the Korean Tree-Trimming Incident,” Joint Forces Quarterly, Summer 2003, p. 110, 111. Mobley states that the August 1976 DEFCON 3 was “the first time it was changed in response to activity in North Korea.”
10. John K. Singlaub, Hazardous Duty: An American Soldier in the Twentieth Century (New York: Summit Books, 1991), as cited in Richard A. Mobley, “Revisiting the Korean Tree-Trimming Incident,” pp. 111, 113-114.
11. U.S. Air Force Gen. Eugene E. Habiger, Stratcom commander, statement before the Senate Armed Services Committee, Authorization for Appropriations Hearing for Fiscal 1998 and Future Years Defense Programs, Senate Hearing 105-37, 105th Congress, March 13, 1997, p. 654.
12. Habiger, conversation with Hans M. Kristensen, August 12, 2004.
13. Gordon H. Chang, “To the Nuclear Brink: Eisenhower, Dulles, and the Quemoy-Matsu Crisis,” International Security, Spring 1988, pp. 96-122; H. W. Brands Jr., “Testing Massive Retaliation: Credibility and Crisis Management in the Taiwan Strait,” International Security, Spring 1988, pp. 124-151.
14. Robert J. Watson, Into the Missile Age 1956-1960, vol. IV of the History of the Office of the Secretary of Defense (Washington, D.C.: Historical Office, Office of the Secretary of Defense, 1997), p. 229.
15. Ibid, p. 241.
16. See: Richard K. Betts, Nuclear Blackmail and Nuclear Balance (Washington, D.C.: Brookings Institution, 1987), pp. 23-31; Leighton, Strategy, Money and the New Look 1953-1956, pp. 536-537; Watson, Into the Missile Age 1956-1960, p. 208; Norman Polmar and John D. Gresham, DEFCON 2: Standing on the Brink of Nuclear War During the Cuban Missile Crisis (Hoboken, New Jersey: John Wiley and Sons, 2006); William Burr, “The October War and U.S. Policy,” Electronic Briefing Book 98, National Security Archive, October 7, 2003; Robert Burns, Associated Press, “U.S. Libya,” April 23, 1996; “Nuclear Weapons Only Option for USA to Hit Buried Targets,” Jane’s Defence Weekly, May 1, 1996, p. 3.
17. William M. Arkin, “Gulf War +10: The Secret Story,” Stars and Stripes, Special Report, n.d. .
18. James A. Baker, III, with Thomas M. DeFrank, The Politics of Diplomacy (New York: Putnam, 1995), p. 359. At the beginning of Operation Desert Storm, according to one unclassified estimate, the United States had some 1,000 nuclear warheads with its military forces in the region. This included 700 bombs and cruise missiles on aircraft carriers, surface ships, and attack submarines, and 300 bombs in Turkey. William M. Arkin et al., “U.S. Nuclear Weapons in the Persian Gulf Crisis,” Greenpeace, January 1991, p. 1.
19. The actual wording of the relevant section in George H. W. Bush’s letter was: “Let me state, too, that the United States will not tolerate the use of chemical or biological weapons, support of any kind for terrorist actions, or the destruction of Kuwait’s oilfields and installations. The American people would demand the strongest possible response. You and your country will pay a terrible price if you order unconscionable actions of this sort.” See also: “Text of Letter from Bush to Hussein,” New York Times, January 13, 1991, as reprinted in Mark Grossman, Encyclopedia of the Persian Gulf War (Santa Barbara: ABC-CLIO, 1995), p. 396.
20. William M. Arkin, “The Nuclear Option and Iran,” WashingtonPost.com (Early Warning Blog), April 19, 2006, blog.washingtonpost.com/earlywarning/2006/04/the_nuclear_option_and_iran.html.
21. Baker with DeFrank, The Politics of Diplomacy, p. 359.