Nuclear Notebook: United States nuclear weapons, 2021 – Bulletin of the Atomic Scientists

At the beginning of 2021, the US Defense Department maintained an estimated stockpile of 3,800 nuclear warheads for delivery by 800 ballistic missiles and aircraft. Most of the warheads in the stockpile are not deployed, but rather stored for potential upload onto missiles and aircraft as necessary. Many are destined for retirement. We estimate that approximately 1,800 warheads are currently deployed, of which roughly 1,400 strategic warheads are deployed on ballistic missiles and another 300 at strategic bomber bases in the United States. An additional 100 tactical bombs are deployed at air bases in Europe. The remaining warheads—approximately 2,000—are in storage as a so-called hedge against technical or geopolitical surprises. Several hundred of those warheads are scheduled to be retired before 2030. (See Table 1.)

Table 1: US nuclear forces, 2021

In addition to the warheads in the Defense Department stockpile, approximately 1,750 retired— but still intact—warheads are stored under custody of the Energy Department and are awaiting dismantlement, giving a total US inventory of an estimated 5,550 warheads. Between 2010 and 2018, the US government publicly disclosed the size of the nuclear weapons stockpile. But in 2019, the Trump administration rejected a request from the Federation of American Scientists to declassify the latest stockpile number, and these numbers remain classified at the time of this