Japanese Prime Minister Yoshihide Suga's surprise decision to step down, a day after seeming to indicate he wished to continue in office and as leader of the Liberal Democratic Party, risks returning his nation to the "one-and-done" era of revolving-door leadership that marked the six years before Mr Shinzo Abe returned to office in 2012, staying on until bad health forced him to leave last September. As with other powerful leaders who seek to continue to wield influence over their office after they leave, Mr Abe had picked Mr Suga, his long-serving No. 2, to succeed him. Mr Suga began well enough, with approval ratings of more than 70 per cent, but those have since slid to less than half of what they used to be.
Mr Suga explained that he is leaving to focus on combating the pandemic. The coming weeks will probably reveal the backstage developments that forced his exit. The Nikkei index's 2.5 per cent rise at its Friday close suggests that investors, if not wider Japan, are not unhappy to see him go. Hints that Mr Suga was losing his standing with Japanese voters - always a key consideration of influential party brass - were on show when his close ally, Mr Hachiro Okonogi, was trounced in the Yokohama mayoral polls. Yokohama happens to be Mr Suga's bailiwick as well.