History · Marshall Islands

Marshall Islands: The Nuclear Atolls

A navigator society scattered across the central Pacific — colonised by Germany then Japan, taken by the US, used for 67 nuclear tests, and now an independent state in free association with Washington and on the front line of rising seas

By Globeway Editorial · 30 September 2026

A narrow strip of palm-covered land dividing a turquoise lagoon from the open ocean
An islet of Majuro Atoll, the capital. The Marshall Islands' 1,200-odd islands add up to about 70 square miles of land, on average only about 7 feet above sea level. (Stefan Lins / Wikimedia Commons · CC BY 2.0)

A country of atolls, and its history of being used

The Marshall Islands are 29 atolls and a handful of islands in the central Pacific, strung in two long chains across some 750,000 square miles of ocean, with only about 70 square miles of land and some 42,000 people — and many more Marshallese now live in the United States. The country is a sovereign republic, but "in free association" with the US, which handles its defence and provides much of its budget. Its modern history is one of being used by outside powers, above all as the testing ground for America's nuclear weapons.

A short history

  1. c. 1000 BCE onward

    Settlement

    Micronesian navigators reach the atolls.

  2. 1788

    Named

    For a British sea captain, John Marshall.

  3. 1885

    German protectorate

    Run through a trading company and the chiefs.

  4. 1914

    Japan

    Seizes the islands, later governing and fortifying them.

  5. 1944

    US conquest

    The battles of Kwajalein and Enewetak.

  6. 1946–1958

    Nuclear testing

    67 US tests at Bikini and Enewetak atolls.

  7. 1954

    Castle Bravo

    The largest US test spreads fallout over inhabited atolls.

  8. 1979

    Constitution

    Self-government begins.

  9. 1986

    Free association

    The Compact with the United States takes effect.

The navigators

Micronesian voyagers settled the Marshalls more than two thousand years ago, and became famous for reading the ocean itself.

A lattice of coconut-frond sticks tied together with small shells at the intersections
A Marshallese stick chart. These lattices mapped the way ocean swells bend around islands; navigators memorised them and left them ashore rather than carrying them. (Library of Congress / Wikimedia Commons)

Society was organised by matrilineal clans under paramount chiefs. Whalers and traders came in the 19th century, American missionaries converted the islands from 1857, and Germany declared a protectorate in 1885, running it lightly through a copra-trading firm. Japan took the islands in 1914 and, from the 1930s, fortified them — before the United States invaded in 1944, bypassing several Japanese garrisons and leaving them to starve.

The Proving Grounds

After the war the Marshalls became part of a US-administered UN "strategic trust", and the US made them its Pacific Proving Grounds. Between 1946 and 1958 it conducted 67 nuclear tests at Bikini and Enewetak atolls, with a combined yield equivalent to more than a Hiroshima bomb every day for twelve years. The people of Bikini were moved off their atoll in 1946; a return in the 1970s ended with a second evacuation in 1978, and contamination still prevents them from living there.

The nuclear legacy

A vast column of water and spray rising from Bikini lagoon around warships during a 1946 nuclear test
The Baker test at Bikini, 1946. The 1954 Castle Bravo test — 15 megatons, far larger than predicted — spread heavy fallout over the inhabited atolls of Rongelap and Utirik, causing lasting radiation illness. (U.S. Department of Defense / Wikimedia Commons)
A large low concrete dome covering a former test crater on a bare coral island
The Runit Dome on Enewetak, a concrete cap over contaminated soil and debris from the tests. It has shown cracking, and there are fears that rising seas could breach it. (U.S. Defense Special Weapons Agency / Wikimedia Commons)

The nuclear legacy — displaced communities, illness, and a decades-long fight over compensation widely regarded as inadequate — remains central to Marshallese politics and identity.

Kwajalein, and independence

Kwajalein Atoll became, and remains, a US missile-testing and space-tracking base. Its Marshallese landowners were relocated to the small island of Ebeye, which became one of the most crowded and under-served places in the Pacific.

A crowded street of low concrete buildings and utility poles on the tiny island of Ebeye
Ebeye, where the displaced landowners of Kwajalein and workers at the US base are packed onto about 80 acres of land. (Erin Magee / DFAT / Wikimedia Commons)

The Marshalls adopted a constitution in 1979 and, in 1986, entered a Compact of Free Association with the United States: full sovereignty and a UN seat, in return for US defence rights, continued use of Kwajalein, economic aid, and visa-free access to the US for Marshallese. A nuclear-claims fund set up under the Compact ran out of money long before it could pay the more than $2 billion a claims tribunal had awarded.

What the Marshall Islands carry

The Marshalls' history has an unusually stark shape: a self-sufficient navigator society, then a century of colonial hand-offs, then use as a weapons range that irradiated and displaced its own citizens. Now the same low atolls face a slower threat — rising seas — and the Marshall Islands have become, at climate negotiations, one of the most insistent voices for limiting warming, having already been sacrificed once for someone else's security.

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