Once NATO had forced the central and eastern European communist states to join hands under the Treaty of Friendship (popularly known as the Warsaw Pact). But with communism losing its ground in Europe and their major power, Soviet Union, breaking into pieces, the treaty lost its value absolutely and finally got dissolved officially in July 1991. Very interestingly, nine of the members and successor states of the Warsaw Pact have joined NATO after the pact was dissolved; proving the deliberate involvement of NATO in the dissolution.
