Senator Tammy Duckworth wrapped up a trip to South Korea and Japan, including a visit to the DMZ, which separates the two Koreas. With the Winter Olympics in South Korea starting next month, Duckworth believes signs of cooperation between the two Koreas make her feel better about athlete safety.

While that's a positive note, Duckworth doesn't believe there has been fundamental change in North Korea's nuclear ambitions.

Duckworth says Japanese officials told her the accidental incoming missile warning in Hawaii gives Americans a sense of the stress that country has faced during the North Korean nuclear crisis.