What is NATO?

NATO, short for North Atlantic Treaty Organization was founded on the 4th of April, 1949 at Washington D. C., United States. However, the seeds for the formation of NATO were sown much earlier, when a charter, called the 'Atlantic Charter', was signed between the United States and the United Kingdom. Commonly, it is known that NATO was formed to counter the threat that the Soviet Union posed to the European countries back then. Now, NATO provides political and military support to its member countries. As of now, the Secretary General of NATO is Jens Stoltenberg. 

History of NATO
NATO was formed due to three main reasons. The first and foremost was definitely the countering of the Soviet Union. Britain had seen a major downfall in its economy as well as its political authority after World War 2. The USSR, on the other hand, was quite powerful and its power had only made its way up after the WWII, given the circumstances European countries were in. It was only logical for these countries to find solace in the hand extended by the United States, which was again, at a very powerful position at that time. NATO also helped in integrating Europe and forbidding the colonial rule of Britain. 
       USSR meant the rule of communism at that time. The Eastern European countries had already fallen prey to communism. There was a fear that the Western European countries might as well become communist. Thus, it became the growing need at that time to have an organization like NATO. 
      Post World War 2, there was a cold War between USA and USSR, which didn't see much of military action, but nuclear weapons were a common sight. This happened due to the fact that USSR had formed the 'Warsaw Pact', similar to NATO, with its member countries, thus strengthening its relations. However, NATO was successful in disintegrating the USSR after the invasion of Soviet Union in Afghanistan as the Warsaw Pact was saw its dissolution in 1991.
      As of the present day, NATO has 30 member countries and its headquarters is located in Brussels, Belgium. The Article 5 of the Treaty is still followed by the Organization, which is also its current motto. The Article 5 says that any harm done to any country would mean a collective rebellion by all the other member countries. NATO played a huge role in unifying Europe and also bringing down the much powerful rule of communist USSR.