New Delhi, Oct. 7 -- Japan's embattled governing party has a new leader: former Economic Security Minister Sanae Takaichi, a hard-line conservative who is poised to become the country's first female prime minister.

Takaichi, 64, immediately needs to seek ways for her long-ruling Liberal Democratic Party to stay in power and regain public support by delivering measures to address inflation and diplomatic challenges such as U.S. President Donald Trump.

A staunch supporter of former Prime Minister Shinzo Abe 's conservative vision, Takaichi is on the verge of losing her party's long-time coalition partner, the Buddhist-backed centrist party Komeito, because of her ultra-conservative politics. Those include a revisionist view of Japan's war...