Barack Obama
U.S. President Barack Obama pauses during remarks on a nuclear deal with Iran at American University in Washington August 5, 2015. Obama's administration continued its plan of releasing more information regarding the U.S.'s nuclear stockpile. The released information shows that the numbers have been decreasing. Reuters/Jonathan Ernst

The Pentagon released the latest number of nuclear weapons in the United States stockpile and declassified other information regarding the country’s nuclear arsenal history Tuesday, continuing the Obama Administration’s five-year-old plan to slowly declassify more information.

The newly disclosed and declassified information details the U.S.’s nuclear disarmament and efforts to reduce its nuclear weapons total between 1962 and last year, as well as details on previous placement of weapons near Japan, the names of and megatonnage of older weapons, and even numbers on weapons stationed abroad.

The declassification process is dubbed the Second Open Government Action plan, which follows the first plan started under President Barack Obama in 2011 to give “the public a more active voice in the U.S. government’s policymaking process,” according to the administration.

The significant drop-off in total nuclear arms from the U.S.’ reported peak total in the late 1960s to now is perhaps the most striking information released. While in the midst of the Cold War with the then-Soviet Union, the U.S. reached a peak of 31,255 weapons in its stockpile in 1967. It had 4,571 weapons in 2015. And between 2014 and 2015, the U.S. reduced its total from 4,717 to 4,571.

A glimpse into efforts to dismantle the devices was also given. Between 1994 and 2015, the documents claim the U.S. dismantled 10,360 weapons, with more than 2,700 of those weapons broken down in 1994 and 1995.

The Pentagon also delved into previously unknown facts about placement of weapons on the island of Okinawa in Japan. The report states weapons were deployed on Okinawa before Japan regained control of it after World War II in May 1972. The two governments held discussions before the reversion about the possibility of “re-introducing” the weapons in the event of an emergency.