The North Atlantic Treaty Organization (NATO) is a military and political alliance of 12 countries. The original founding members are the United States, the United Kingdom, Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, and Norway.

Several new countries have sought membership in NATO. Enlargement has been controversial because of tensions with non-member Russia, which has a history of aggression against other countries.

Warsaw Pact

The Warsaw Pact was a military alliance of communist nations in Eastern Europe. It was founded in 1955 to counter the North Atlantic Treaty Organization (NATO).

The Pact included Bulgaria, Czechoslovakia, East Germany, Hungary, Poland, and Romania. It was dissolved in 1991 when Soviet military commanders relinquished control of Warsaw Pact forces.

The Pact was divided into two parts: the Political Consultative Committee handled political matters, and the Combined Command of Pact Armed Forces controlled multi-national forces assigned to Warsaw Pact countries. These organizations met infrequently and were dissolved after 36 years of existence.

1991-1992

As the Soviet Union and Warsaw Pact collapsed in 1991, the US government was constructing a new security architecture that would help foster and fortify emerging European democracies. It also wanted to enlarge NATO, which it saw as a way to cement its influence in Europe.

However, most officials were reluctant to expand NATO eastward, fearing that it could rankle Russia’s leaders at a fragile and transitional moment, according to James Goldgeier, an American University professor who has written about the alliance.

Instead, the Clinton administration sought to build up a new security structure with Central European nations like Poland and the Czech Republic, along with other former Warsaw Pact countries. It crafted a plan called the Partnership for Peace, which provided for joint exercises and participation in operations, as well as consultations with NATO partners should they feel threatened by threats to their own security.

1993-1994

During the 1993–1994 period, Poland was in the process of becoming a member of NATO. The first step towards enlargement was the establishment of the Partnership for Peace (PfP) program in 1994.

The aim of the PfP was to improve the relationship between post-communist countries and the Alliance by organizing common exercises and peace missions.

In July 1997, during a NATO summit in Madrid, Poland, Hungary, and the Czech Republic were invited to begin accession talks. The negotiations lasted until 1999 when Poland became a full-fledged member of the Alliance.

1995-1996

In 1995, President Bill Clinton stated that the first new member states from Central and Eastern Europe should be admitted to the Atlantic Alliance by 1999.

The Visegrad countries—Poland, the Czech Republic, and Hungary—were the first to press for membership.

They emphasized the importance of building a solid foundation for peace and stability, fostering democratic processes, and developing free markets.

Washington adapted to these calls with the Partnership for Peace (PfP) program, designed to strengthen political and military cooperation throughout Europe. It is aimed at expanding stability, diminishing threats to peace, and building stronger relationships with NATO allies.

1997-1999

The period from 1997 to 1999 is often seen as the most tumultuous in the history of Poland. It saw the death of a princess, the Millennium Bug, and the dissolution of the Warsaw Pact.

The 1997–1999 period also marked the beginning of a new chapter in Poland’s relationship with NATO. It was during this time that the country began talks about possible membership in the Alliance.

This was a positive step from the Polish perspective, and it was an important one because it opened the door to the enlargement of NATO to Central and Eastern Europe. But President Bill Clinton’s recommendation that NATO accepts its first new members by 1999, on the 50th anniversary of the Washington Treaty, was not an easy sell to Moscow.

2000-present

The 2000–present period saw the growth of NATO from 12 original members to 30 today, with a number of countries from former Soviet territories, including Poland and Hungary, joining. The alliance is an international military and political organization.

The aims of the military organization are to ensure collective defense through political and military means in case one member is attacked. This is based on Article 5 of the treaty, which says that “an armed attack against one or more of them (states) shall be considered an attack against all.”