Warsaw Pact
On 25 February 1991, the Pact was declared at an end at a meeting of defense and foreign ministers from the remaining member states meeting in Hungary. On 1 July 1991, the Czechoslovak President Václav Havel formally declared an end to the Warsaw Treaty Organization of Friendship, Co-operation, and Mutual Assistance which had been established in 1955. The USSR itself was dissolved in December 1991.

Q: Who was the president of Czechoslovakia during the dissolution of the Warsaw Pact?
Václav Havel