If successful, diplomats draw up treaties-contracts between countries-which must be ratified and, one hopes, observed. If one country feels a treaty harms it there is nothing to stop it from violating the bargain. Countries enter into and observe treaties because it suits them. Some observers say the United States and Soviet Union, both relative newcomers to the world of great-power politics, were unskilled at diplomacy, too unwilling to compromise. The climate of mistrust between them was one of the hallmarks of the Cold War.