If you've been following the news for the past couple of weeks you've no doubt seen lots of hand wringing about North Korea's missile tests. To summarize, they've popped off a couple of missiles that seem to have intercontinental capability, i.e., they could, in theory travel from North Korea to the vicinity of the United States or Canada and deliver their payload. The missiles in question keep landing in the ocean, which strongly suggests deliberate targeting to prove launch and control capability as well as making it more difficult for other countries to get hold of the hardware for analysis. That payload, of course, is what has many worried. Additionally, it's been observed that the US military's anti-ballistic missile capability is less than stellar. Official word from the Pentagon is that they're confident that they could handle such a problem, some evidence backs that up, and other evidence casts doubt upon them, such as failing 75% of the time. Coupled with North Korea kicking up propwash in the international media about US and South Korean forces training together about cutting loose if the two countries don't knock it off (spoiler alert: they haven't and aren't).
On the other hand, earlier this year North Korea successfully put a satellite into orbit (even though it's tumbling, which makes it useless for anything other than a proof-of-concept) and detonated a bomb powerful enough to register as a seismic event several thousand miles away. Regardless of what one may think these are not events to dismiss lightly because they demonstrate dual-use technical capability; the rocket booster used to put the satellite into orbit could also be used to propel a military payload into the airspace of another country, and even if the bomb detonated on 6 January 2016 wasn't actually a hydrogen bomb, it was certainly powerful enough to level a city.
That said, here's my two cents: Sit down, have another cup of coffee, and find something interesting to do.
No, really. Don't worry about this.
Let's be honest here... neither myself not anybody who reads this post have a snowball's chance in a blast furnace of doing anything about North Korea possibly lobbing the equivalent of several kilotons of TNT (smaller than the Hiroshima and Nagasaki bombs) over top of where we happen to be living now or in the forseeable future. Looking at an unclassified map of what their missile capability can reach right now in one of the news articles I've linked to, that's maybe a third of the United States (looking from the west coast and going inland), a lot of Canada, all of Japan, much of China, practically all of Australia, and a great deal of Russia. Other countries with more advanced capability already have more landmass on this planet covered as potential targets but I digress...
Now let's hypothesize that North Korea gets a hair up its nose and lobs a 7 kiloton warhead at where you happen to be living. Please load this site in another tab and follow along with me. Plug in your hometown and a 7 kiloton airburst, and click the big, shiny red button. See that number of estimated fatalities that's probably in the five digits? One of those digits in all probability is either you or me. That's right, in all likelihood we bought the farm in the blast. If the big honking fireball somehow didn't touch the ground (perhaps reducing us to ash if it didn't blast us out of existence entirely), if we weren't reduced to paste by the overpressure flattening a building before we could get out the front door, then complications of third degree burns or acute radiation poisoning would probably kill you and I a short time later.
In point of fact, we might not even know what hit us. That missile would be traveling so fast and the detonation so violent that it's unlikely that we'd have enough time to do anything more than turn in the general direction of North Korea, let alone let fly with the appropriate salute before that nuke went off. We probably wouldn't have time to turn, even.
So, let's get on with our lives. Scale and scope being what they are let's concentrate on what we can feasibly change and live in ways that we're not going to regret right before we jack the big black.