Cooper: The long game in South Korea

South Korean President Moon Jae-in, left, talks with North Korean leader Kim Jong Un at a restaurant in Pyongyang, North Korea, during negotiations between the two in September.

A report Monday highlighting the location of 13 North Korea secret missile facilities shouldn't sink talks between the Asian country and the U.S. over North Korea's nuclear program, but it should confirm the soundness of the "trust but verify" strategy we and others have suggested for such negotiations.

"Trust but verify," ironically a Russian proverb, was a phrase frequently cited by former U.S. President Ronald Reagan about compliance in nuclear disarmament talks with the former Soviet Union in the 1980s.

In June, in a move four previous presidents were unable or unwilling to pull off, President Donald Trump met face to face with North Korea leader Kim Jong Un about the possibility of North Korea dismantling its nuclear program. Although strides were made toward a permanent peace between North and South Korea, the nuclear issue would be a work in progress.