The Stockholm International Peace Research Institute (SIPRI) is an independent international institute and a globally respected think tank dedicated to research into conflict, armaments, arms control, and disarmament.
The institute was established in 1966 following a decision by the Swedish Parliament and is based in Stockholm, Sweden. The idea was first proposed in 1964 by Swedish Prime Minister Tage Erlander to commemorate Sweden's 150 years of unbroken peace and to conduct scientific research on international peace and security. Its founding purpose was to address the problems of armaments and disarmament, particularly against the backdrop of the Cold War arms race.
SIPRI works by providing data, analysis, and policy recommendations based on open sources to policymakers, researchers, and the public. Its core mechanism is maintaining authoritative, long-running databases, such as the SIPRI Military Expenditure Database (tracking spending since 1949) and the SIPRI Arms Transfers Database (tracking transfers since 1950). It also publishes the annual SIPRI Yearbook, which provides a comprehensive overview of developments in international security.
The institute's work connects directly to major international concepts and agreements, including the 2013 Arms Trade Treaty (ATT), the 2001 UN Programme of Action on SALW, and the framework of the United Nations. Its research on nuclear forces is a key reference for understanding the status of the Nuclear Non-Proliferation Treaty (NPT) and the now-expired New START Treaty.
While its core mission of independence and focus on disarmament remains, the institute recently adopted the SIPRI Strategy 2024–29 to navigate a changing global landscape. A key recent finding, highlighted in the SIPRI Yearbook 2026, is that states are increasingly relying on nuclear weapons as instruments of national power, which reverses decades of efforts to reduce their role.