Japan's ruling party is secure under any new leader

Significance

The winner will become prime minister and lead the party into a general election that must take place before the middle of November. Four candidates are running. The incumbent bureaucratic reform minister and 'vaccine czar' Taro Kono is the clear frontrunner, but much could change over the next twelve days.

Impacts

• More North Korean missile tests and other provocations would benefit the more hawkish candidates, Fumio Kishida and Sanae Takaichi.
• A win for Takaichi, who is backed by former Prime Minister Shinzo Abe, would make Abe the 'power behind the throne'.
• Japan's foreign partners are wary of a return to the 'revolving door' pattern of weak leaders serving one-year terms, but this is unlikely.