NATO stands for the North Atlantic Treaty Organization. NATO was created in April of 1949 when 13 countries signed a treaty stating if one of the countries got attacked they all got attacked. Communist Russia is a large reason as to why Iceland, Portugal, Norway, Denmark, Italy, Great Britain, the Netherlands, France, Luxembourg, Belgium, the United States and Canada. When all of these countries signed NATO they agreed to the terms that if one country was attacked they would all provide mutual help to the country in distress that has been attacked. A few years later three more countries decided to join NATO. These countries were West Germany, Greece and Turkey. The main purpose of NATO was to form an alliance with as many countries as possible.
