Between 643 and 668 CE, East Asia was engulfed by a war that drew in nearly every state in the region. During the preceding centuries, peripheral states used tribute and investiture relations to balance competing Chinese empires against each other, but the unification of China under the Sui disrupted this strategy. As tension emerged between Koguryŏ and the Chinese empires, Silla and Paekche repeatedly sought to advance their interests by drawing the Sui and Tang into conflicts on the Korean peninsula. The result was a massive reconfiguration of the region: Paekche and Koguryŏ were destroyed, Silla consolidated control of the Korean peninsula, and Yamato entered a period of rapid centralization, while the Tang retreated. These events demand our attention because they offer insight into the flexibility of East Asian tribute and investiture relations, which shifted but endured throughout this period of extreme volatility.