At the signing ceremony of the North Atlantic Treaty on April 4, 1949, then-U.S. President Harry Truman noted that if this “simple document” had existed in 1914 and 1939, “it would have prevented the acts of aggression that led to two world wars.” The newly created alliance, he suggested, would ensure peace by deterring potential aggressors.
The success of this collective security strategy is reflected in the number of countries that have taken advantage of NATO’s open door policy. Since 1949, the alliance has expanded from 12 to 32 members, with Finland and Sweden being the most recent additions. Member States must now commit to admitting Ukraine.
Including Kiev in NATO is important for several reasons. For starters, any doubt about the alliance’s commitment to defend current or future members invites aggression. Russia is an example of this. The decision to suspend Ukraine and Georgia’s membership aspirations at the 2008 Bucharest summit led to Russia’s invasion of Georgia later that year. Similarly, ignoring Moscow’s annexation of Crimea in 2014 resulted in its full-scale invasion of Ukraine in 2022.
