US President Donald Trump made a stunning concession to North Korean leader Kim Jong Un yesterday, about halting military exercises, pulling a surprise at a summit that baffled allies, military officials and lawmakers from his own Republican Party.

At a news conference after the historic meeting with Kim in Singapore, Trump announced he would halt what he called "very provocative" and expensive regular military exercises that the United States stages with South Korea.

That was sure to rattle close allies South Korea and Japan. North Korea has long sought an end to the war games...