This article is a general, nonpartisan explainer. It describes the United States unless stated otherwise, and details change over time, so check official sources for the latest.
Arms control refers to agreements among states to limit the number, type, or use of weapons. It does not require friendship. Rivals have made treaties because they share an interest in avoiding accidents, avoiding costly arms races, and keeping conflicts manageable.
Well-known agreements
- The Nuclear Non-Proliferation Treaty (opened for signature 1968) aims to prevent the spread of nuclear weapons.
- The Strategic Arms Limitation Talks and later strategic arms reduction treaties limited U.S. and Soviet or Russian nuclear forces.
- The Intermediate-Range Nuclear Forces Treaty of 1987 eliminated a class of missiles, and the United States withdrew from it in 2019.
- The Chemical Weapons Convention bans chemical weapons.
The status of some treaties has changed in recent years, so check current sources for the latest.
Verification
Agreements work only if parties believe that others are complying. Verification can include satellite imagery and other national technical means, data exchanges, on-site inspections, and notifications of tests or movements.
Why agreements are difficult
- New technologies can outpace treaty definitions.
- Parties differ on what to count and how.
- Domestic politics may make ratification hard.
- Some states stay outside treaties altogether.
Alternatives to treaties
Not all arms control is formal. States can adopt unilateral restraints, parallel declarations, confidence-building measures, or hotlines that reduce the risk of accidental escalation.
Arms control rarely ends rivalry, but it can make competition safer and more predictable.
