Still vital: NATO at 70: Roberto Rabel notes the anniversary of the treaty that has underpinned Western security for seven decades.

• Author: Rabel, Roberto
• Position: ANNIVERSARY

On 4 April 2019, the world's most successful peacetime military alliance will mark its 70th anniversary. Over that time, the North Adantic Treaty Organisation (NATO) has been the critical mainstay of the West's commitment to international security. While established during the Cold War, NATO not only outlasted that ideological confrontation but also has since expanded its membership and scope.

When signed in Washington DC on 4 April 1949, the North Adantic Treaty was a shared response by Western democracies to a perceived threat from Soviet-led communism. A year earlier, Great Britain, France, Belgium, the Netherlands and Luxembourg had concluded the Brussels Treaty pledging mutual assistance in the event of a threat to any of them. Equally concerned about the menace of communism, Harry Truman's Democratic administration moved to secure bipartisan support for an American military alliance with Europe. Republican Senator Arthur Vandenburg obliged by proposing a congressional resolution in May 1948, which facilitated negotiations culminating in the North Atlantic (or Washington) Treaty.

In addition to the United States and Brussels Treaty states, the signatories included Canada, Denmark, Iceland, Italy, Norway and Portugal. Through Article 5 of the treaty, they agreed to regard a military attack against any of their nations within North America and Europe as an attack against all of them.

The treaty was notably significant for the United States, creating its first peacetime alliance outside the Americas. It required overcoming historically isolationist forces in Congress, especially within the Republican Party. It was also a powerful symbol of Washington's willingness to assume the burdens of leadership of the so-called free world, by linking American interests, national resources and political capital to the collective defence of Western Europe.

The North Atlantic Treaty signing did not itself launch a meaningful international military organisation. Only after the Korean War broke out in 1950 did member states act to implement the treaty through an integrated military structure. This involved various steps, including creation of the role of secretary-general of NATO as civilian head of the organisation in 1952. That same year, Greece and Turkey joined NATO, followed by West Germany in 1955.

Reflecting the Cold War context, the Soviet Union reacted by forming the Warsaw Pact with its East European satellite states in 1955. For the ensuing 35...