For a country who loves war so much why is america afraid of north korea so much?

We are not... We have ballistic missile system which will blow up the nukes before they hit any mainland. North Korea is not a threat to the United States. Ha, you know what I would like to see? North Korea trying to invade the US, that would be fun to watch. Don't worry we will come knocking at North Korea's door soon enough, more like kicking in the door.