The Treaty of San Francisco was signed on September 8, 1951, and came into effect on April 28, 1952, officially ending the state of war between Japan and the Allied Powers and serving as Japan's peace treaty following World War II. Notably, China was not invited to participate in the treaty discussions due to disputes over which government—Republic of China (ROC) or People's Republic of China (PRC)—legitimately represented the Chinese people. The treaty had Japan renounce all claims to Taiwan, the Pescadores, the Spratly Islands, and the Paracel Islands.

The treaty's ambiguous wording regarding Taiwan's political status has led to the Theory of the Undetermined Status of Taiwan. This theory suggests that the sovereignty of either the ROC or PRC over Taiwan may be illegitimate or temporary and emphasizes that the issue should be resolved through the principle of self-determination. The theory generally leans toward Taiwanese independence and does not typically claim that Japan should still have sovereignty over Taiwan, although there are some exceptions.