A missile like the one tested Wednesday could reach Washington, D.C., and the entire U.S. Eastern Seaboard, some observers believe.
On his first day on the peninsula, the president again pushed Pyongyang to abandon its nuclear weapons but sounded optimistic, saying “ultimately, it’ll all work out.”
Responding to lawmakers' questions, the Pentagon says a ground invasion is the only way to locate and destroy all components of that country's nuclear weapons program.
During a visit to South Korea, the U.S. secretary of defense said "we are doing everything we can" to avoid war with North Korea.
"It is imperative that Pyongyang and Washington find some way to ease the escalating tension and reach a lasting, peaceful agreement," the former president writes.
Plummeting in the polls, the president may be tempted into "Wag the Dog"-type military action against the two countries.
The award went to the International Campaign to Abolish Nuclear Weapons, composed of activists pushing for a global treaty to ban the cataclysmic bombs.
The president has no desire to seek diplomatic solutions in the standoff over nuclear weapons and ballistic missiles with Kim Jong Un.