What Does NATO Stand For?

What does NATO stand for, letter by letter?

• N, North: the northern part of the Atlantic Ocean region.
• A, Atlantic: the ocean that links the North American members with the European ones.
• T, Treaty: the North Atlantic Treaty, the agreement signed in 1949 that created the alliance.
• O, Organization: the standing body of staff, councils and commands that carries out the treaty.

So NATO is the organization built around one treaty. The name tells you where it began and what holds it together, but it does not limit members to the coast. Countries far from the ocean have joined over the years.

How the alliance works

The core promise sits in Article 5 of the treaty: an armed attack against one member is treated as an attack against them all, and each member agrees to help in the way it judges necessary. That clause has been invoked once, after the attacks on the United States on September 11, 2001.

Other key points:

• Consensus: the main council makes decisions only when every member agrees.
• Civilian leadership: a secretary general chairs meetings and speaks for the alliance.
• Shared planning: members train together and use common standards, so their equipment and forces can work side by side.
• Joining: new members must be invited, and every existing member must approve.

Views on NATO

NATO is often in the news, and people describe it in different ways. Supporters see it as a reason major wars between its members have been avoided and as a deterrent to outside threats. Critics in various countries question how costs are shared, whether the alliance should keep growing, or how it affects relations with nonmembers. Debate about defense spending targets comes up often at its summit meetings.

This page describes what the term means rather than taking a side. Other defense and agency letters appear in our government and military acronyms collection.

The NATO alphabet

Many people meet the letters through the NATO phonetic alphabet, the set of code words used to spell things clearly over radio and phone: Alpha, Bravo, Charlie, Delta and so on to Zulu. The alliance adopted it in the 1950s, and it is now used by pilots, police, the military and customer service staff around the world.

Other letters with roots in emergency radio include SOS.

How to say and write NATO

Because people pronounce it as a word, "NAY-toh," NATO counts as a true acronym. Write it in capitals without periods. Since it starts with an N sound, use "a NATO member," not "an." French speakers use a different acronym, OTAN, from the French name of the treaty, and NATO's official languages are English and French.

Why are some short forms spoken like words while others get read letter by letter? See acronym vs abbreviation.

NATO and look-alike groups

• NATO vs UN: the United Nations includes nearly every country and deals with many issues. NATO is a defense alliance of a smaller group of countries.
• NATO vs the European Union: many countries belong to both, but the EU is mostly about trade, law and economics, while NATO is about defense. Some EU members are not in NATO, and some NATO members are not in the EU.
• NATO vs the Warsaw Pact: the Warsaw Pact was a rival alliance led by the Soviet Union. It ended in 1991, the same year the USSR broke up.