The Cannikin test, conducted by the United States Atomic Energy Commission, took place on Amchitka Island, Alaska, and marked a significant moment in the Cold War era nuclear arms race. On November 6, 1971, the U.S. detonated what was to be the largest underground hydrogen bomb ever tested, with an explosive yield estimated at 5 megatons. This test followed an earlier series of nuclear tests and aimed to assure the functionality of the U.S. nuclear arsenal in an evolving geopolitical landscape characterized by tension with the Soviet Union.

Amchitka Island, located in the Aleutian Islands, was chosen due to its remote location and geological conditions that could absorb the concentrated force of the explosion. The Cannikin test was conducted deep underground, approximately 1,200 feet below the surface, which minimized radioactive fallout. The underground test was part of a broader strategy to guarantee the United States maintained a deterrent capability against potential adversaries without resorting to atmospheric nuclear testing, which had been banned following the 1963 Nuclear Test Ban Treaty.

As the world entered the 1970s, the arms race between the U.S. and the Soviet Union intensified, and nuclear tests like Cannikin signaled advancements in thermonuclear weapons technology. The Cannikin test, while illustrating the U.S. commitment to nuclear superiority, raised concerns about the environmental and health effects of such testing, particularly for the local ecosystems and indigenous populations of the Aleutian Islands. Following the test, there would be increased scrutiny and protest against nuclear testing.