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.
In the case of Russia during the Putin era, this level of threat is excessive as Russia can bomb back. So the threat has been reduced to: do as you are told or we will impose sanctions.
Sanctions are an assertion of hegemony of one country over another. They are an assertion that the imposer of sanctions has extra-legal international authority to tell other sovereign states what to do or to suffer consequences if they do not.