(August 1, 1975), major diplomatic agreement signed in Helsinki, Finland, at the conclusion of the first Conference on Security and Co-operation in Europe (CSCE; now called the Organization for Security and Co-operation in Europe (Security and Co-operation in Europe, Organization for)). The Helsinki Accords were primarily an effort to reduce tension (Cold War) between the Soviet and Western blocs by securing their common acceptance of the post-World War II status quo in Europe (Europe, history of). The accords were signed by all the countries of Europe (except Albania) and by the United States and Canada. The agreement recognized the inviolability of the post-World War II frontiers in Europe and pledged the 35 signatory nations to respect human rights and fundamental freedoms and to cooperate in economic, scientific, humanitarian, and other areas. The Helsinki Accords are nonbinding and do not have treaty status.

Sought by the Soviet Union (Union of Soviet Socialist Republics) from the 1950s, a European security conference was proposed by the Warsaw Pact in 1966 and was accepted in principle by the North Atlantic Treaty Organization. In 1972 preparatory talks on the ambassadorial level opened in Helsinki. Over the next several months, an agenda was prepared consisting of four general topics, or “baskets”: (1) questions of European security, (2) cooperation in economics, science and technology, and the environment, (3) humanitarian and cultural cooperation, and (4) follow-up to the conference.

Following a foreign ministers' meeting in Helsinki in July 1973, committees met in Geneva to draft an agreement, a process that lasted from September 1973 to July 1975. The principal interest of the Soviet Union was in gaining implicit recognition of its postwar hegemony in eastern Europe through guarantees of the inviolability of frontiers and noninterference in the internal affairs of states. In return for their formal recognition of this, the United States and its western European allies pressed the Soviet Union for commitments on such issues as respect for human rights, expansion of contacts between eastern and western Europe, freedom to travel, and the free flow of information across borders. The Final Act, signed at a summit meeting in Helsinki, reflected both viewpoints. The agreement in effect marked the formal end of World War II, since it recognized all the European national frontiers (including Germany's division into two countries) that had arisen out of that war's aftermath.

The guarantees of human rights contained in several of the Basket III provisions proved to be a continuing source of East-West contention after the accords were signed in 1975. Soviet crackdowns on internal dissent in the late 1970s and early '80s prompted Western nations to accuse the Soviets of having entered into the human-rights portions of the accords in bad faith, while the Soviets insisted that these were purely internal matters.

Follow-up conferences to the Helsinki Accords were held at Belgrade, Yugoslavia (now in Serbia and Montengero), in 1977–78; Madrid, Spain, in 1980–83; and Ottawa, Ontario, Canada, in 1985. The collapse of communism in eastern Europe in 1989–90 and the pending reunification of Germany necessitated a second summit meeting of the CSCE in order to formally end the Cold War: this summit took place in Paris in November 1990.