WASHINGTON -- In his 1949 speech at the Washington signing of the North Atlantic Treaty, U.S. President Harry S. Truman set the tone with simple words and a straightforward message.
"For us, war is not inevitable," Truman said. "Men with courage and vision can still determine their own destiny. They can choose slavery or freedom, war or peace. I have no doubt which they will choose."
Seventy-five years later, the alliance this week will mark the moment that 12 allies put pen to paper to commit to the transatlantic relationship and address the Soviet threat to peace and security in Europe.
Having seen the Iron Curtain divide the continent, the 12 countries -- Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom, and the United States -- agreed to the principle of collective defense, which is still at NATO's core today.
Outlined in Article 5 of the NATO treaty, the principle states that if one of the signatory countries is attacked, it shall be considered an attack against all other signatories.
It is sure to be noted during the conference that Article 5 has been invoked only once -- following the September 11, 2001, terrorist attacks on the United States.
Ironically, at the founding of NATO, the United States was one of the most skeptical of the treaty and Article 5.
The United States, whose nuclear guarantee would give the treaty its eventual strength, was wary of automatic declarations of war because the U.S. Constitution gives Congress alone the power to declare war, John Deni, a NATO historian and professor at the U.S. Army War College, told RFE/RL.
Washington had, however, signed the 1947 Rio Pact, which ensured mutual assistance throughout the Western Hemisphere but lacked any military commitment. Deni said this opened the door for five European partners -- Belgium, France, Luxembourg, the Netherlands, and the United Kingdom -- to approach the United States with the aim of European collective defense.
"We were reluctant partners," Deni said. "This was the brainchild of the Brits. The United States wanted economic rebirth from Europe."
Although the American public was told the treaty was a way to oppose communism, Deni said a "hidden rationale" for the alliance came from the U.S. need for economic stability and success in Europe.
In Truman's words, NATO would be "a bulwark which will permit us to get on with the real business of government and society -- the business of achieving a fuller and happier life for all our citizens."
Deni says events in 1948 -- a coup in Czechoslovakia and the Soviet blockade of Berlin – had alerted the United States to the impact of instability on the European economy and "changed the minds in Washington."
But the treaty was written "in a way that we Americans insisted upon," Deni said. It did not require an automatic declaration of war and therefore won strong bipartisan support in Congress.
By early 1949, a draft was ready to go, and the treaty was signed on April 4 in Washington at a meeting of the heads of state of the 12 founding countries. The Soviet Union was put on notice that the North Atlantic Treaty Organization meant its members would stand in common defense.
As Washington prepares to host a NATO summit on July 9-11 and mark the alliance's 75 years, the importance of Article 5 and NATO's milestones have been on the agendas at several think-tank events in the U.S. capital.
Some speakers have noted that NATO's unity was put to the test at the end of the Cold War, when the alliance no longer faced the Soviet threat that Max Bergmann, director of CSIS's Europe Center, said it was "founded to focus on."
Other speakers recalled that some policymakers and politicians argued at the time that NATO was no longer needed, while others favored adapting to the new world order.
Russia's full-scale invasion of Ukraine in February 2022 and emerging regional threats to NATO are expected to be major topics at the summit in Washington on July 9-11.
Phillippe Dickinson, deputy director of the Transatlantic Security Initiative at the Atlantic Council, said the end of the Cold War drove "a real change in NATO's posture and purpose in the world."
NATO created its Partnership for Peace program during this period, inviting Russia in 1994 to be part of it, an arrangement that lasted for 20 years until its forcible annexation of Ukraine's Crimean Peninsula in 2014. Next came two major waves of post-Cold War enlargement, in 1999 and 2004, when several European countries and the Baltics joined.
The alliance later shifted to focus on international operations, counterterrorism, and crisis management. NATO allies also began peacekeeping missions outside of the North Atlantic, including in Iraq and Kosovo. In addition to peacekeeping, NATO has been increasing cooperation with countries outside of the North Atlantic, especially in the Indo-Pacific.
Four of NATO's 35 partner nations -- Australia, Japan, New Zealand, and South Korea -- have been invited to the alliance's events on Indo-Pacific threats at the upcoming summit.
Aside from the Indo-Pacific, the majority of NATO's other 31 partner states come from Eastern Europe, the Mediterranean, and the Middle East.
All of NATO's members and partners, aside from the suspended Afghanistan, Belarus, and Russia, have been invited to the summit. This includes Georgia, despite its adoption of what many call a Russia-influenced "foreign agent" law on May 28, and Ukraine, which is desperate for a path to membership. A senior U.S. official told reporters in Washington that NATO allies will present a "bridge-to-membership" scenario for Ukraine at the summit.
Russia's full-scale invasion of Ukraine in February 2022 and emerging regional threats to NATO are expected to be major topics at the summit, but it will also be clear that in its 75 years the alliance has changed in an effort to take on far more than the Soviet threat it was founded to contain.
Nevertheless, Truman's words in 1949 could be echoed by any Western leader today: "Our method of achieving international unity through the voluntary association of different countries dedicated to a common cause is an effective step toward bringing order to our troubled world."