How the U.S. & North Korea could stumble into World War III

U.S. military planners are increasingly concerned that tensions on the Korean peninsula could unintentionally trigger a wider war as Trump and Kim Jong Un hurl unusually personal attacks online.

U.S. military officials increasingly worry that a mistake or miscommunication - even more than an intentional act of war - could start a nuclear conflict in Korea.

A North Korean provocation, a U.S. warning shot, malicious hackers or a simple accident could be the cause that starts a new war between two nations with a long history of tensions and suspicion.