FAS Nuclear Notebook
A deep dive into the world's nuclear arsenals
The FAS Nuclear Notebook is co-authored by Hans M. Kristensen and Matt Korda and published bi-monthly in the Bulletin of the Atomic Scientists. Each issue provides a snapshot of a nuclear-armed country weapons programs or a global nuclear weapons matter. The FAS Nuclear Notebook is one of the most widely sourced reference materials worldwide for reliable information about the status of nuclear weapons, and it is the most visited section of the Bulletin of the Atomic Scientists web site. Starting in 2020, the Bulletin only offers the Notebooks in web format, but full PDF formats are still available from Taylor & Francis. Because of their importance as a resource to an informed public debate about nuclear weapons, the FAS Nuclear Notebooks are freely available on the Internet.

Russia
Nuclear forces by year
February 2022: Russian nuclear weapons, 2022
March 2021: Russian nuclear forces, 2021
March 2020: Russian nuclear forces, 2020
September 2019: Tactical nuclear weapons, 2019
March 2019: Russian nuclear forces, 2019
May 2018: Russian nuclear forces, 2018
September 2017: Worldwide deployments of nuclear weapons, 2017
March 2017: Russian nuclear forces, 2017 (Because of frequent access problems with this issue, a backup copy is available here)

United States
Nuclear forces by year
January 2021: U.S. nuclear forces, 2021
January 2020: U.S. nuclear forces, 2020
September 2019: Tactical nuclear weapons, 2019
May 2019: U.S. nuclear forces, 2019
March 2018: U.S. nuclear forces, 2018
November 2017: A history of U.S. nuclear weapons in South Korea
September 2017: Worldwide deployments of nuclear weapons, 2017
January 2017: U.S. nuclear forces, 2017
March 2016: U.S. nuclear forces, 2016
January 2016: Declassified: U.S. nuclear weapons at sea during the Cold War

France

United Kingdom
Older Nuclear Notebooks all the way back to the first issue in May 1987 can be found here (for those that are missing, see Google Books here). The FAS Nuclear Notebook is researched and produced by the analysts at the Federation of American Scientists. Previously it was produced by the Natural Resources Defense Council, headed by Robert S. Norris, and called the NRDC Nuclear Notebook.
The research that makes the FAS Nuclear Notebooks possible is generously supported by the John D. and Catherine T. MacArthur Foundation, the New-Land Foundation, the Ploughshares Fund, the Prospect Hill Foundation, the FTX Future Fund and Longview Philanthropy, the Stewart R. Mott Foundation, the Future of Life Institute, Open Philanthropy, and individual donors. The statements made and views expressed are solely the responsibility of the authors.