The North Atlantic Treaty Organization is one of the few formal military alliances that remains. Its twin, the Warsaw Pact has long ceased to exist. NATO has dual origins, first it was a more formalized version of the Western Allies. Following World War I alliances took on a more ideological character and the Allies represented "democratic" values. World War II ended American isolationism quite effectively. NATO helped to integrate the Americans into the old Entente, or perhaps better put, it superseded it.
The second reason for NATO was American policymakers' determination to curtail Communist expansion. NATO is a mutual defence organization primarily. Early in its existence states on the frontline of the Cold War, ex. Turkey, joined NATO as a bulwark against the Soviet Union. The hope was to end communist interference and Soviet aggression.
However, history fondly likes to remind us that continuity and change move hand in hand. Russian imperial expansion switched to Soviet communist encroachment and now we're in an age of Russian nationalist-economic aggression.
NATO expanded in to Eastern Europe in the wake of the Cold War's conclusion. In 2007 I may have written that NATO is an outdated institution. A massive political-military alliance against Russia seemed provocative and unnecessary. And then Putin ordered the invasion of Georgia and Ukraine. Suddenly NATO's justification seems much more relevant.
I provide all this context because it was recently reported that Canadian forces were reinforcing the NATO garrisons in the Baltic region. The Baltic countries: Estonia, Latvia and Lithuania, historically languished under Russian/Soviet oppression. Efforts were made to wipe out their distinct cultures through colonization. With what has happened in Russian areas of Ukraine it is not extreme to think that these countries could be next.
It is certainly moral to defend these small states from the Russian behemoth. Outside of NATO these nations would be utterly defenceless against Russian aggression. It does raise questions though. Would Canadians be willing to go to war over Estonia? The answer, I presume, is no, but it's a question we must now ask ourselves and whether or not we intend to uphold our obligations.
It is easy to dismiss Russia's actions as regional aggression, but it is important to recall that we share a massive territory with the Russians - the Arctic. Canada needs as many friends as it can muster if/when Russia makes military and diplomatic efforts to exert greater control over the region. Canada is a small democratic nation, it has an interest in standing with its peers and smaller sisters. One hopes NATO never has to be called to action. That said, NATO may deserve a serious rethink. Its intervention in Libya suggested perhaps a new future for the alliance, but the Ukrainian conflict suggests that its future may look much more like its past for now.