Moon Jae-in’s Gamble on North Korea Bears Fruit

After historic summit between President Trump and Kim Jong Un, South Korea’s leader finds his position vastly improved

Jonathan Cheng in Seoul and

Andrew Jeong in Singapore

June 15, 2018 6:00 a.m. ET

Last fall, South Korean leader Moon Jae-in’s North Korea policy appeared to be stuck in the mud.

Months into his presidency, Pyongyang and Washington were exchanging threats and shows of force. North Korea was ignoring Mr. Moon’s repeated pleas for dialogue. And U.S. President Donald Trump was publicly rebuking Mr. Moon for appeasing North Korea.

After...