Marshall Islands

Between 1946 and 1958, the United States conducted 67 nuclear tests in the Marshall Islands, 23 at Bikini Atoll and 44 at Enewetak Atoll. The detonations were conducted atmospherically and underwater, spreading radioactive fallout by wind and water currents. Among the 67 nuclear tests was Castle Bravo, the largest U.S. nuclear test to this day, conducted in the Bikini Atoll. Castle Bravo yielded 15 megatons, 1,000 times more powerful than the atomic bomb dropped on Hiroshima, leaving the Marshall Islands experiencing one of the worst exposures to ionizing radiation with fallout spreading 7,000 square miles downwind. The total energy yield of all the tests conducted in the Marshall Islands was equivalent to more than 7,000 Hiroshima bombs.

The Runit Dome, a remnant of nuclear testing in the Marshall Islands holding nuclear waste.

Nuclear Colonialism

Nuclear colonialism refers to the practice whereby colonial powers chose territories inhabited by marginalized and indigenous populations to conduct nuclear testing with little regard for the effects on the local populations. When the United States government selected sites for nuclear testing, these colonialist attitudes shaped major decisions.  The United States chose the Marshall Islands because it was a “remote” territory, distant from American populations, and under U.S. military occupation since 1944. The decision did not consider the Marshallese people who called the chosen Atolls of Enewetak and Bikini their homes, or those who lived on neighboring islands.

Lasting Nuclear Legacy

Many Marshallese were forcibly relocated to smaller islands with fewer resources and some have not been able to return home as their land, soils, and foods remain heavily contaminated. Even when relocated, populations suffered from health issues stemming from fallout exposure and food insecurity. Victims of the United States’ nuclear testing in and around the Marshall Islands suffer to this day from high rates of cancers, including thyroid and leukemia, reproductive disorders, and other ailments such as diabetes, arising from changes in diet.

Not only have the Marshallese experienced devastating health consequences but significant radiological contamination remains on the islands, including in the locally grown foods, rendering parts of the Marshall Islands uninhabitable. This contamination robs displaced Marshallese people of the opportunity to safely inhabit their native lands and live according to their culture and tradition.  Many displaced Marshallese now live in northwest Arkansas or Hawaii.

Environmental Impact

With lasting radiation in many parts of the Marshall Islands and contaminated food and water sources, living in certain parts of the atolls is deemed unsafe, and other areas suffer from scarcity of uncontaminated resources.  From 1978 to 1980, the US government organized a radiological cleanup of Enewetak Atoll,  collecting contaminated materials from different islands which were then deposited in an unlined nuclear test crater on the island of Runit. To contain this radioactive waste, an 18 inch thick concrete dome was constructed at sea level. Although original plans included a lined bottom, this safety measure was scrapped for cost and speed. The dome, referred to by the people of the Marshall Islands as the Tomb, contains over 100,000 square feet of radioactively contaminated soil and debris. As sea levels rise and catastrophic weather events become more common, the aging dome’s risk of failure increases.

The Compact of Free Association

Almost thirty years after the last U.S. nuclear test, a bilateral agreement entered into force between the Marshall Islands and the U.S. in 1986. The Compact of Free Association (COFA) recognized the sovereignty of the Marshall Islands, but also gave the U.S. ‘exclusive’ military access to Marshallese territory. Moreover, COFA acknowledged the 67 nuclear tests and instantiated a Nuclear Claims Fund to compensate victims of nuclear testing. While the Nuclear Claims Tribunal awarded the Marshall Islands over $2 billion dollars in damages, the Nuclear Claims Fund only granted $150 million dollars, less than 8% of the Tribunal’s award. 

The Compact of Free Association grants Marshallese people access to U.S. social services and the ability to travel and work in the U.S without a visa as a form of compensation.

Nuclear Zero Lawsuits

On April 24, 2014, the Republic of the Marshall Islands (RMI) filed lawsuits against all nine Nuclear Weapon States in the International Court of Justice and, separately, against the United States in U.S. Federal District Court. The Nuclear Age Peace Foundation served as a consultant to the RMI on these lawsuits, working closely with the Marshallese government and assembling the US legal team.

At the time of these lawsuits, the Nuclear Non-Proliferation Treaty (NPT) had been in force for over 44 years. The Nuclear Weapon States rely heavily on nuclear weapons and are engaging in modernization programs to keep their nuclear weapons active for decades to come, acting in violation of Article VI of the NPT, which calls for nuclear disarmament.  The cases were ultimately dismissed by the International Court of Justice and the U.S. Ninth Circuit Court of Appeals.

Further Reading

  • Runit Dome covering nuclear test waste in the Marshall Islands

    Cracks appear in Runit Dome amid sea level rise in Marshall Islands

    The following article was originally published in ABC News on March 14, 2026 by Kyle Evans. A new ABC News report examines cracks in the Runit Dome in the Marshall Islands, where radioactive waste from U.S. nuclear testing was buried decades ago. With sea levels rising and the structure showing signs of deterioration, the story underscores the long-term human and environmental consequences of nuclear weapons testing. Cracks appear in Runit Dome amid sea level [...]

  • Runit Dome covering nuclear test waste in the Marshall Islands

    The Marshall Islands: U.S. Testing At Bikini Atoll and Enewetak Atoll

    By Mohammed Alkurashi | Updated April 23, 2026 Background Between 1946 and 1958, the United States conducted sixty-seven nuclear tests (23 at Bikinit Atoll and 44 at Enewetak Atoll), and among the 67 nuclear tests, Castle Bravo was the largest U.S. nuclear test to this day (Makhijani, 2025). Castle Bravo had a yield of 15 megatons, a thousand times more powerful than the atomic bomb dropped on Hiroshima, leaving the Marshall Islands with prolonged [...]

  • Expendable Lands and Colonial Legacies: Nuclear Testing in the Marshall Islands

    Nuclear colonialism refers to the practice whereby colonial powers choose territories inhabited by marginalized and indigenous populations to conduct nuclear testing with little regard for the effects on the local populations. The term encapsulates the colonialist view of Indigenous peoples and their territories as expendable. This attitude of expendability is foundational to colonialism and its legacies; nuclear colonialism represents one particularly dramatic phase in a lengthy, destructive history and its perpetuating legacy. Beginning in [...]

Remembering Castle Bravo 69 Years Later

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Castle Bravo Blast (Public Domain) Castle Bravo is the largest nuclear weapon test the United States (US) ever conducted. It was a seminal event in the nuclear testing history of the Marshall Islands. It is also part of a shameful legacy for those of us who consider ourselves American. Today, the Marshallese people [...]

The Hidden Legacy of the Runit Dome

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As a third-year college student, I have struggled my way through enough United States history courses to know that our government has not always acted in the most benevolent of ways in the past, particularly when dealing with smaller, vulnerable countries. I have always liked to think that most of these transgressions, though unacceptable, are [...]