North Korea announced today that it has tested a hydrogen bomb. There was a detection of a 5.1 magnitude earthquake in an area associated with previous nuclear weapons test by the North. This would be the 4th nuclear test for them since 2006 and represents a major upgrade in capabilities if it is indeed an H-bomb.
North Korea already has missiles capable of reaching the west coast of the United States of America. It can be reasonably assumed that they have taken a step towards a long term goal of building a nuclear warhead small enough to fit onto a long range missile capable of striking North America.
This world is getting more and more dangerous all the time.