It was held by the Japanese from 1914 until its capture by the United States in February 1944 during World War II, then became Naval Base Eniwetok.

The first European colonizers to Enewetak, Spanish explorer Álvaro de Saavedra Cerón, arrived on 10 October 1529.

[14] With the rest of the Marshalls, Enewetak was captured by the Imperial Japanese Navy in 1914, during World War I and mandated to the Empire of Japan by the League of Nations in 1920.

The Japanese administered the island under the South Seas Mandate, but mostly left affairs in hands of traditional local leaders until the start of World War II.

When the Gilberts fell to the United States, the Imperial Japanese Army assigned defense of the atoll to the 1st Amphibious Brigade, formed from the 3rd Independent Garrison, which had previously been stationed in Manchukuo.

Some 2,586 of its 3,940 men were left to defend Eniwetok Atoll, supplemented by aviation personnel, civilian employees, and laborers.

[17] In 1950, John C. Woods, who executed the Nazi war criminals convicted at the Nuremberg Trials, was accidentally electrocuted there.

During the three-year, US$100 million cleanup process, the military mixed more than 80,000 cubic meters (100,000 cu yd) of contaminated soil and debris[25] from the islands with Portland cement and buried it in an atomic blast crater on the northern end of the atoll's Runit Island.

[25] The United States government declared the southern and western islands in the atoll safe for habitation in 1980,[c] and residents of Enewetak returned that same year.

[d] Soil that could not be effectively treated for human use was removed and used as fill for a causeway connecting the two main islands of the atoll (Enewetak and Parry).

[30] A report by the US Congressional Research Service projects that the majority of the atoll will be fit for human habitation by 2026–2027, after nuclear decay, de-contamination and environmental remediation efforts create sufficient dose reductions.

[30] A lawsuit by Marshallese arguing that "changed circumstances" made Nuclear Claims Tribunal unable to make just compensation was dismissed by the Supreme Court of the United States in April 2010.

[41] US Navy and Marine units based at Eniwetok included: The airstrip is now abandoned and its surface partially covered by sand.

Following its capture on 22 February, Seabee's from the 110th Naval Construction Battalion expanded the base, building a coral-surfaced parking area and shops for minor aircraft and engine overhaul.

MILS was developed and installed by the same entities that had completed the first phase of the Atlantic and U.S. West Coast SOSUS systems.

A MILS installation, consisting of both a target array for precision location and a broad ocean area system for good positions outside the target area, was installed at Eniwetok as part of the system supporting Intercontinental Ballistic Missile (ICBM) tests.

Other Pacific MILS shore terminals were at the Marine Corps Air Station Kaneohe Bay supporting Intermediate Range Ballistic Missile (IRBM) tests with impact areas northeast of Hawaii and the other ICBM test support systems at Midway Island and Wake Island.

[57][58][59] This article incorporates public domain material from the Air Force Historical Research Agency