The Treaty between the United States of America and the Russian Federation on Measures for the Further Reduction and Limitation of Strategic Offensive Arms, known as New START or the Prague Treaty, was signed in Prague on 8 April 2010 by Presidents Barack Obama and Dmitry Medvedev. The Protocol is an integral part and contains three annexes. Authentic texts: English and Russian. Entry into force on 5 February 2011, by the exchange of instruments of ratification. It is not START I, which had expired in 2009, not START II, which never entered into force, and not the Moscow Treaty of 24 May 2002 (SORT), which it supersedes.

The central limits, which the Parties had seven years from entry into force to meet: 700 deployed intercontinental ballistic missiles, submarine-launched ballistic missiles and heavy bombers equipped for nuclear armaments; 1,550 warheads on those deployed systems, with each heavy bomber counted as one warhead; 800 deployed and non-deployed launchers together with heavy bombers. Each Party determines the structure of its forces within the ceilings. Conversion and inspection procedures are not transcribed as a handbook.

Verification, at the level of principle: on-site inspections, notifications, a continuing exchange of data, and national technical means. A Bilateral Consultative Commission is established. Unilateral statements attached to the Senate transmittal are not legally binding. The Treaty does not limit tactical systems and, according to the letter of transmittal, contains no constraints on planned United States missile defence.

The United States Senate gave advice and consent in the winter session of 2010; the Federal Assembly of Russia ratified in early 2011. Original duration: ten years, with an option to extend for up to five years. The Parties extended it into early 2026. On 21 February 2023 Russia announced a suspension of participation, without withdrawal; the Treaty later expired after the extended term.

Cover: the signing in Prague; a contemporary photograph, without restating the date. Wikimedia Commons, free licence.

Sources consulted: New START; New START Treaty (U.S. Department of State).