Today NATO serves one master. However, the United States does not share its plans, secrets, strategic plans with NATO.
The realist theory of international relations dominating the USA assumes that the national interest of the state is superior to the international law and treaties signed with its allies. In other words, Article 5 of the North Atlantic Treaty would be fulfilled by the United States only in a situation, when the US interests agree with its legal obligations.
Article 5 of the North Atlantic Treaty is the critical component of the Alliance – it assumes that if a NATO Ally is a victim of an armed attack, every other member of the Alliance will consider this act of violence as an armed attack against all members and will take the actions it deems necessary to assist the Ally attacked. In other words, Article 5 is the cornerstone of NATO – it has been invoked only once in history as a response to the terrorist attacks of September 11, 2001.
The United States is the founding member of NATO and plays a crucial role in European and transatlantic security – since the end of WWII, the US troops based in Europe guaranteed the security of its European allies. Currently, the US is increasing its military presence in Europe (particularly in Central and Eastern Europe) in order to protect this region against two primary threats: Russia's "malign influence" and international terrorism.
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