Nuclear security

Status of World Nuclear Forces

More than two decades after the Cold War ended, the world’s combined inventory of nuclear warheads remains at a very high level: approximately 15,700. Of these, around 4,100 warheads are considered operational, of which about 1,800 US and Russian warheads are on high alert, ready for use on short notice.

Despite significant reductions in US, Russian, French and British nuclear forces compared with Cold War levels, all the nuclear weapon states continue to modernize their remaining nuclear forces and appear committed to retaining nuclear weapons for the indefinite future. For an overview of global modernization programs, see this 2014 article.

The exact number of nuclear weapons in each country’s possession is a closely held national secret. Despite this limitation, however, publicly available information, careful analysis of historical records,  and occasional leaks make it possible to make best estimates about the size and composition of the national nuclear weapon stockpiles...