The U.S. government weighed its chances of convincing Tokyo in the late 1960s to allow the deployment of nuclear weapons in Japan if a crisis in East Asia were to break out, according to newly declassified documents.

The idea, which was never proposed because its chances of success were apparently considered "very slight," offers a look into how Washington sought to expand its military footprint in the region after World War II and the Korean War.

The atomic bombings of Hiroshima and Nagasaki had left the Japanese public with a strong aversion to nuclear weapons, with the prohibition of their possession, manufacture and introduction in Japanese territory — first outlined in 1967 — coming to form the core of Japan's nuclear policy.