The discussions culminated in the STARTs, or Strategic Arms Reduction Treaties, which are based on START I (a 1991 agreement between the United States and the Soviet Union) and START II (a 1993 agreement between the United States and Russia, which was never ratified by the United States), limiting capabilities with several warheads and limiting the number of nuclear weapons on both sides. A successor to START I, New START, was proposed and finally ratified in February 2011. On May 24, 2002, Presidents George W. Bush and Vladimir Putin signed the Strategic Offensive Reduction Treaty (SORT), under which the United States and Russia reduced their strategic arsenals to 1,700-2,200 heads. The warhead border came into force and expired on the same day, December 31, 2012. Although the two sides have not agreed on specific counting rules, The Bush administration stated that the United States would reduce only warheads used on strategic active-duty delivery vehicles (i.e. “operational” warheads) and would not count warheads removed from service and placed in warehouses or warheads on delivery vehicles that are obsolete or repaired. The limits of the agreement are similar to those provided for START III, but the contract did not require the destruction of delivery vehicles, as START I and II did, nor the destruction of warheads, as planned for START III. The treaty was approved by the Senate and Duma and came into force on 1 June 2003. SORT was replaced by New START on February 5, 2011. New DEPART Given the many asymmetries in both countries, the introduction of equivalent restrictions required fairly complex and precise provisions. At the time of the signing, 1,054 land-based ICBMs were in service in the United States, none of which were under construction; the Soviet Union had an estimated 1,618 in operation and construction.
The launchers under construction could be completed. Neither party would begin to build additional ICB launchers during the duration of the agreement – which excludes the relocation of existing launchers. Light or older ICBM launchers cannot be converted into launchers for modern heavy ICT. This prevented the Soviet Union from replacing older missiles with missiles such as the SS-9, which was the largest and most powerful missile in the Soviet inventory in 1972 and which was of particular concern to the United States. Nixon was proud to have reached an agreement through his diplomatic capabilities that his predecessors failed to reach.