North Korea's hidden artillery pieces have managed to deter outside invaders for decades, but with Kim scrambling to perfect his fleet of intercontinental ballistic missiles and top US officials viewing Pyongyang's
nuclear ambitions like a ticking time bomb, the use of the US's most advanced aircraft in exercises signals the US is serious about the possibility of war.
As policy in South Korea looks
like shifting, many sceptics remain who think that no amount of talking to Kim Jong - un will persuade him to renounce either his despotic power or his
nuclear ambitions.