The dissolution of the Soviet Union removed the constraint on Washington’s unilateralism. The neoconservatives, who had just risen to power, seized the opportunity and replaced diplomacy with threat and coercion. One infamous example is from the George W. Bush regime when the Deputy Secretary of State, Richard Armitage, told Pakistan to do as you are told or you will be bombed into the stone age. We have this on the authority of the president of Pakistan himself, who did as he was told.
https://www.paulcraigroberts.org/2018/06/05/absence-diplomacy-isolating-washington-paul-craig-roberts/