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 exposure to ionizing radiation.

Legal Disputes

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 (Tupuola, 2025). 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, it only granted $150 million dollars (Kimball, 2023).

Marshallese individuals filed suits in U.S. district courts, which were eventually dismissed—citing lack of jurisdiction (Republic of the Marshall Islands v. United States, 2017) . In 2014, the Marshall Islands filed a suit at the International Court of Justice (ICJ) against all nuclear-armed states, accusing the U.S. of violating Article VI commitments under the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) as well as customary international law obligations to pursue good-faith negotiations towards the complete elimination of nuclear weapons; and the case was dismissed two years later (Schmitz, 2016).

This was not the first time the ICJ was referred to for nuclear disputes. Australia and New Zealand both sued France in 1973 for its open-air nuclear testing in the Pacific. France subsequently made public declarations to stop and move its testing underground.

The Nuclear Half-Life

Nuclear bombs detonated by the U.S. contained a variety of chemical  elements, namely: cesium-137, strontium-90, plutonium-239/240, and americium-241. Below is the half-life of each element and how long it takes for it to decay to safe levels (Environmental Protection Agency, 2026):

  • Cesium-137: ~30 years (safe after ~300 years)

  • Strontium-90: ~29 years (safe after ~300 years)

  • Plutonium-239: ~24,000 years (safe after ~240,000 years)

  • Plutonium-240: ~6,560 years (safe after ~65,000 years)

  • Americium-241: ~432 years (safe after ~4,000 years)

Scientifically speaking, the legacy of nuclear testing in the Marshall Islands is one that simply cannot be wiped away by a one-time payment. Continued support for Marshallese individuals affected is a necessary step to ensuring that Marshallese people enjoy their human right to life, namely through well-funded healthcare services intended to address the rising cancer rates stemming from the series of U.S. nuclear testing. Subsequently, the UN Human Rights Council adopted resolution 57/26 (2024), mandating technical assistance by the Office of the United Nations High Commissioner for Human Rights (OHCHR) to address the human rights implications of nuclear testing in the Marshall Islands.

Bibliography

Arjun, M. (2025). The legacy of U.S. nuclear testing in the Marshall Islands. Retrieved from https://ieer.org/wp/wp-content/uploads/2025/06/Legacy-of-US-nuclear-testing-in-the-Marshall-Islands-Arjun-Makhijani-June-2025.pdf.

Daryl G., K. (2023). U.S., Marshall Islands sign deal on nuclear testing impacts. Retrieved from https://www.armscontrol.org/act/2023-03/news/us-marshall-islands-sign-deal-nuclear-testing-impacts.

Environmental Protection Agency. (2026). Radionuclides. Retrieved from https://www.epa.gov/radiation/radionuclides.

Jared G., T. (2025). The compacts of free association.

  1. L. Herman, “Nuclear Tests Case: Australia v. France; New Zealand v. France”, Comment, (1976-1977) 3:1 DLJ 288.

Nuclear Tests (Australia v. France), Judgements, I.C.J. Reports 1974, p. 253.

Republic of the Marshall Islands v. United States, 865 F.3d 1187 (9th Cir. 2017).

Schmitz, Maitê de Souza. (2016). Decision of the international court of justice in the nuclear arms race case. Retrieved from https://journals.law.harvard.edu/ilj/2016/11/decision-of-the-international-court-of-justice-in-the-nuclear-arms-race-case/.

United Nations Human Rights Council 57/26 (2024). Technical assistance and capacity-building to address the human rights implications of the nuclear legacy in the Marshall Islands.(A/HRC/57/26). https://digitallibrary.un.org/record/4063938?ln=en&v=pdf.