Beginnings of NATO

The Treaty of Brussels was a mutual defence treaty against the Soviet threat at the start of the Cold War. It was signed on 17 March 1948 by Belgium, the Netherlands, Luxembourg, France, and the United Kingdom and was the precursor to NATO.

The Soviet threat became immediate with the Berlin Blockade in 1948, leading to the creation of a multinational defence organization, the Western Union Defence Organisation, in September 1948.

However, the parties were too weak militarily to counter the Soviet Armed Forces. In addition, the communist 1948 Czechoslovak coup d'état had overthrown a democratic government, and British Foreign Minister Ernest Bevin reiterated that the best way to prevent another Czechoslovakia was to evolve a joint Western military strategy. He got a receptive hearing in the United States, especially with the American anxiety over Italy and the Italian Communist Party.

In 1948, European leaders met with US defence, military, and diplomatic officials at the Pentagon, exploring a framework for a new and unprecedented association. The talks resulted in the North Atlantic Treaty, and the United States signed on 4 April 1949. It included the five Treaty of Brussels states, as well as the United States, Canada, Portugal, Italy, Norway, Denmark and Iceland.

The first NATO Secretary General, Lord Ismay, stated in 1949 that the organization's goal was "to keep the Russians out, the Americans in, and the Germans down". Popular support for the Treaty was not unanimous, and some Icelanders participated in a pro-neutrality, anti-membership riot in March 1949.

The creation of NATO can be seen as the primary institutional consequence of a school of thought called Atlanticism, which stressed the importance of trans-Atlantic cooperation. The members agreed that an armed attack against any of them in Europe or North America would be considered an attack against them all. Consequently, they agreed that if an armed attack occurred, each of them, in the exercise of the right of individual or collective self-defense, would assist the member being attacked and take such action as it deemed necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area.

The treaty does not require members to respond with military action against an aggressor. Although obliged to respond, they maintain the freedom to choose the method by which they do so.

That differs from Article IV of the Treaty of Brussels, which clearly states that the response is military in nature. NATO members are nonetheless assumed to aid the attacked member militarily.

The treaty was later clarified to include both the member's territory and their "vessels, forces or aircraft" above the Tropic of Cancer, including some overseas departments of France.

The creation of NATO brought about some standardization of allied military terminology, procedures, and technology, which, in many cases, meant European countries adopting US practices.

Roughly 1300 Standardization Agreements (STANAG) codified many of the common practices that NATO has achieved.

The 7.62×51mm NATO rifle cartridge was thus introduced in the 1950s as a standard firearm cartridge among many NATO countries. Fabrique Nationale de Herstal's FAL, which used the 7.62mm NATO cartridge, was adopted by 75 countries, including many outside NATO.

Also, aircraft marshalling signals were standardized so that any NATO aircraft could land at any NATO base. Other standards such as the NATO phonetic alphabet have made their way beyond NATO into civilian use.