The U.S. has conducted twenty more nuclear tests than the rest of the world combined, according to a new analysis.


The United States has conducted more nuclear weapon tests than the rest of the world combined, according to a new analysis published on Real Clear Science.

Real Clear Science compiled a list counting the number of tests each country that is known have conducted nuclear tests has carried out since the dawn of the nuclear era.

The United States leads the pack with 1,032 nuclear weapons tests, with Russia (including the Soviet Union) coming in at a distant second with 715 tests. France has conducted the third most with 198 tests, while China and the United Kingdom have both carried out 45 of them.

After that the numbers drop off even more substantially with India having carried out three confirmed tests and six claimed ones, North Korea’s three tests since 2009, and Pakistan having carried out two confirmed tests and six claimed ones, according to Real Clear Science.

Although not included on the list, Israel is widely believed to have carried out a covert nuclear test off the coast of South Africa in 1979, which was captured by the U.S. Vela satellite.

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Counting Israel’s test and India and Pakistan’s confirmed tests, the world excluding U.S. has carried out 1,012 tests. If India and Pakistan’s non-confirmed tests are included, that number rises to 1,019.

Thus the U.S. has carried out either twenty or thirteen more nuclear tests than the rest of the world combined, according to the Real Clear Science data.

To be fair, an argument could be made that the U.S. was likely to conduct more nuclear tests than the other nuclear weapon states merely because it was pioneering much of the nuclear weapon technology. This includes the first atomic bomb in July 1945 and the first thermonuclear bomb in November 1952.


The perils of being a pioneer in the field was made clear by the Bravo test the U.S. conducted at Bikini Atoll in the Marshall Islands In 1954. One of the new nuclear designs being tested contained lithium-7 isotope, which gave it an unexpected boost.

Ultimately the yield of this device was two and a half times larger than what was expected— 15 megatons or 1,000 times as powerful as the bomb used on Hiroshima— and it provoked one of the worst nuclear fallout incidents in U.S. history. The radiological fallout ultimately spread across 11,000 square miles, and contaminated nearby islanders, U.S. naval personnel, and a Japanese fishing boat— the Lucky Dragon #5— provoking something of a diplomatic crisis with Tokyo.

The U.S., Soviet Union, and United Kingdom were also the first to institute controls on nuclear weapons testing with the signing of the Limited Test Ban Treaty (LTBT) in 1963. The LTBT prohibited nuclear tests from being carried out in the atmosphere, underwater, or in space but did allow for underground nuclear tests because of the difficulties in detecting these and thus being able to identify violations.

The Soviet Union would ultimately violate the LTBT and nuclear tests resumed for a time among the major nuclear powers. However, the end of the Cold War in 1991, as well as technological advances that enabled countries to better monitor and detect nuclear tests, made a Comprehensive Test Ban Treaty (CTBT) possible. Negotiations over a CTBT opened at the United Nations in 1993, and three years later the treaty was open for signatures.

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Although the U.S. played a large role in drafting the Treaty, the U.S. Senate failed to ratify it during Clinton's administration. Upon taking office, President Obama vowed that he would renew an effort to get the Senate to ratify the CTBT. The fierce Congressional opposition to the New START treaty with Russia suggested such an effort would be futile, and unsurprisingly there hasn’t been much movement on this front.

Despite its non-ratification of the CTBT, the U.S. has not tested nuclear weapons since 1992. Instead, it relies on computer modeling to ensure the safety and effectiveness of its nuclear arsenal. This technology has come a long way and a 2012 National Academies report concluded, “So long as the nation is fully committed to securing its weapons stockpile and provides sufficient resources for doing so, the U.S. has the technical capabilities to maintain safe, reliable nuclear weapons into the foreseeable future without the need for underground weapons testing.”