European hysteria over Russia ensures that Europe will do whatever the US tells them to because Europeans are terrified of losing US military protection. Don't take my word for it though, as Sabine Weyand, Directorate-General for Trade at the EU commission, explains: "If you didn't hear me say the word 'negotiation'—that's because there wasn't one." The U.S. dictated terms in a "strategic compromise, not an ideal economic solution" that European leaders know will destroy their economies. Europe agreed because it is unable to manage its own security. "We have a land war on the European continent. And we are completely dependent on the United States," so there you have it.

https://www.sz-dossier.de/tiefgaenge/das-waren-keine-verhandlungen-0142c461

There's a similar dynamic at play with Japan and occupied Korea who are terrified of both China and DPRK. Hence, the US can force all the vassals who are militarily dependent on having imperial protection to pay tribute to the empire.