Taiwan marks 75 years since Japan gave up its claim to the island — a reminder that Beijing never legally received it, which is good news for Taiwan's case for self-rule and bad news for China's claim.

• The 1951 San Francisco treaty had Japan renounce Taiwan and the Penghu islands, but never named China as the new owner.
• The Republic of China was not among the 49 signers, and Japan later said it had no standing to hand Taiwan to Taipei.
• US officials through 1949 and 1950 repeatedly said Taiwan's legal status was unsettled until a peace treaty settled it, and Chiang Kai-shek privately called Taiwan a trusteeship.
• The negotiator who steered Japan's renunciation, John Foster Dulles, was the grandson of the American who drafted the 1895 document handing Taiwan to Japan in the first place.
• Seventy-five years on, Taiwan is Asia's most vibrant democracy, the world's 20th largest economy, and the third biggest exporter to the US.

Outlook: Expect continued pressure to teach the treaty in Taiwanese schools and to use it as legal ground against Beijing's claim, with the island's chip-driven economy raising the stakes for the free world.