In other stories, we read that Kim is unlikely to launch a pre-emptive strike as he realises that would be the end of his reign and the destruction of North Korea. The real risk is that a fool like Trump would launch an attack on North Korea and Kim to feel that he has nothing to lose. Reminds me of Dubya's knee-jerk and irrelevant attack on Iraq after 9/11 - that pretty much led to what bin Laden wanted, American economic ruin and the riling up of all kinds of Muslim populations against the US and the West, including the rise of ISIS. I think there's far more benefit to working the diplomatic channels and reducing the proliferation of nukes than there is to building defence systems that can never be 100% effective.