As World War II wound down, the Allied forces advanced on Berlin from two directions. The Americans, British and French resistance advanced from the west, and Russia from the east. Hitler committed suicide, the war ended and everyone headed home. Except not everyone did.
The Americans, British and French turned around and went home after helping prop up local governments of those who had opposed the Nazis. The Russians never really left. If they did leave, they propped up puppet regimes that the Soviet leaders in Moscow would exterminate if any resistance to Soviet rule cropped up. Instead of restoring democratic rule, the Soviets installed communist regimes.
On March 5, 1946, less than a year after concluding the war, British Prime Minister Winston Churchill gave one of his most famous speeches at Westminster College in Fulton, MO. He declared, "From Stettin in the Baltic to Trieste in the Adriatic, an iron curtain has descended across the continent." Thus began the Cold War. The Soviet Union, it was clear, intended to spread its communist ideology across the world and would work to destabilize the West.
The Western allied powers, along with a rebuilt Germany and Italy, collaborated on what to do to protect themselves from the Soviet threat. Many of the allies were broken and still had shattered infrastructure. What rose up from this was the North Atlantic Treaty Organization. The treaty was signed on April 4, 1949, and to this day NATO remains the strongest and most important military alliance in the history of the world.
Article 5 of NATO's treaty is the key provision. It states that an attack on one member is an attack on all members and all members of NATO will respond in kind. NATO is funded through a uniquely fair rule. Each member state agrees to contribute an amount of money based on a percentage of Gross National Income. As a nation becomes wealthier, the amount it contributes increases and as it becomes poorer, the amount it contributes decreases. The United States, being the wealthiest nation on the planet, has always contributed the most, but its total share has gone down over time as the European nations became stronger and more stable in the post-World War II era.
With the fall of the Soviet Union, NATO expanded and many of the former Soviet bloc nations behind the iron curtain joined. The Baltic nations of Latvia, Lithuania, and Estonia, all three of which resisted Soviet rule during their occupation, were three of the first Eastern European countries to join. Poland, which the Nazis and Soviets had carved up, also joined. Soon, almost every former Soviet controlled regime behind the iron curtain had joined NATO. Together, they pledged they'd never led a Russian threat destabilize them again.
These nations paid terrible prices for their Soviet occupation. Millions of citizens disappeared over the years, murdered by Soviet agents. Neighbors turned against neighbors. Joining NATO and moving toward Western culture has not only brought about stability, but also peace of mind. Now, in the 21st century, Russia is again saber rattling and trying to destabilize many of these countries.
Only once has NATO ever acted upon Article 5. It was not a Russian invasion, but a terrorist attack on the United States. On September 11, 2001, NATO allies surrounded our airspace and interests around the world, protecting us while we buried our dead and sorted out what happened. Then they joined us in Afghanistan to shut down the Taliban.
It is therefore unfortunate that a major party candidate for President of the United States would suggest NATO should be a shakedown scheme where the United States does not return the favor of alliance unless our allies "pay up." Friendship and alliances do not come to bullies demanding lunch money for protection. They come through shared interests. Our NATO allies protected us and helped us after September 11, 2001, for the first time activating Article 5 of the NATO treaty. It is awful to think our response should be these nations, once torn apart by communism and now threatened by a dangerously resurgent Russian menace, should have to pay us to do the right thing.