I have a BA in Political Science with my concentration on Economics and Foreign affairs. Among the Political scientist community its not really an issue. Political instability in the US is a much bigger threat.
---Things to consider---
North Korea is well aware they cannot take the US and South Korea, so North Korea is just doing what we call "Saber rattling" to make themselves look strong. Every time North Korea has made massive displays of force and tensions reach a high point, world powers often throw money and humanitarian aid to the Hermit Kingdom. This makes Kim Jong Un look strong to his people and often calms them down for a period of time. North Korea is suffering from a famine and more then 50% of its population is starving and malnourished. North Korea uses its military to "exploit" food and other resources which is why seem "erratic" in there military displays. Mainly its only done when they want food or support aid.
If you really think war is imminent look at China's border policy. China stands the most to lose even if they dont go to war. Should there be war and WHEN the US and South Korea win, China knows there would me a migration of millions of refugees. The only way to stop this would be to have a massive military presence to stop them (Little known fact this is one of the main reasons they participated in the 1950 Korean war). If we start seeing massive buildup on military forces by China along the northern border then people would really start to reassess the situation.
Another factor is that War tends to build up a presidents approval ratings (Not commenting on the current US president just stating a fact). Aggressive military action in the eyes of the american voter in most cases tends to increase approval ratings.
(sorry for the errors, PC down so I'm using my new tablet. Trying to get a feel for it)