In an interview with Karel Hvížďala (included in "To the Castle and Back"), Havel expressed his feeling that it was his most important accomplishment as president to have contributed to the dissolution of the Warsaw Pact. According to his statement the dissolution was very complicated. The infrastructure created by the Warsaw Pact was part of the economies of all member states, and the Pact's dissolution necessitated restructuring that took many years to complete. Furthermore, it took time to dismantle the Warsaw Pact's institutions; for example, it took two years for Soviet troops to fully withdraw from Czechoslovakia.