Before World War II, Britain had its trading empire, France had its empire, Japan had its empire, etc. Oceanic trade between nations not in the same empire ran a high risk of the cargo simply being confiscated or destroyed by one of the imperial navies. A key pillar of the US's strategy in the Cold War was to use its naval supremacy to prevent the return to the imperial trading system; in other words, it extended to nations an offer of the ability to trade freely on the world's oceans in exchange for that nation's joining the US in opposing the Soviets.
The United States also suppressed wars. For example, the 2 nations that arguably had the most powerful pre-WWII militaries (Britain and France) allied with Israel to attack Egypt after Egypt nationalized the Suez Canal, but the United States, worried that the Soviets could enter the conflict, threatened Britain and France with economic sanctions unless they withdrew, which they did.