If the obviously staged celebrations in Pyongyang are any indication, North Korea has successfully managed to get something into orbit. No one is entirely sure what it is yet -- more than likely a very simple satellite of some kind -- but nonetheless it appears that the North Korean rocketry program has managed to get off the ground.
While the US media is doing a great job of making this sound frightening and producing poorly rendered computer animations of a rocket launch, it has done little to explain what this actually means for the ongoing staring contest between North Korea and the rest of the world.
The answer is: not a great deal.
Up until a point rockets can be thought of as a peculiar sort of artillery shell. They fly in roughly parabolic arcs not unlike a gunshot and can hit things that are far away. Since the North Koreans haven't previously managed to get anything into orbit, their previous rocket and missile tests fall into this category. Such vehicles can hit targets which are very very far away, but they're different from vehicles capable of reaching orbit.
When something is in orbit around the Earth it is moving fast enough that the rate at which the curvature of the Earth falls off at about the same speed that the object falls towards the planet's surface. This means that it just never stops falling. With almost no atmospheric drag it never slows down either. That's how orbit works.
The upshot of that is that an object in orbit can easily pass over almost any spot on the planet without expending much in the way of additional fuel. Once something is in orbit it can effectively reach any spot on Earth. This is called "sub-orbital bombardment" and sounds more than a little bit frightening.
But "reach" is a difficult problem. Getting something into orbit means moving it at about 7 kilometers per second or somewhere north of 15,000 miles per hour. While the North Koreans have managed to get something into orbit that doesn't mean that they have mastered the next step: re-entry.
Steering something at 15,000 miles per hour is hard. Doing so while it's being buffeted by the Earth's atmosphere is yet harder. Doing so while it's compressing the air in front of it into a luminous sheath of incandescent plasma which blocks out radio communications raises the difficulty even further and keeping it from being incinerated by the aforementioned plasma makes the whole process downright challenging.
And that's all before developing the precision to hit a target smaller than, say, the Continental United States.
Add onto those challenges the problem of the sensitive electronics, unstable chemicals, or fragile DNA of a nuclear, chemical, or biological weapon and one can see why North Korea is, even in the most optimistic of its scenarios, a very long way from turning its recent launch into something of military significance.
While it is tempting to point to North Korea's entry into space as a watershed moment for its relationship with the rest of the world, that too would be unrealistic. While American and Japanese diplomats will pontificate about North Korea's violation of UN resolutions and condemn its saber rattling, the fact is that the regime has been isolationist and unconcerned with the UN's prohibitions for decades. If anything, the recent launch further proves the absurdity of attempting to embargo technologies from militarily interested countries. Absent a willingness to actually bring military action against industrial and research facilities, international hand-wringing, sanctions, and other diplomatic measures serve only to coerce those powers willing to be coerced.
North Korea's launch is then, as The Bard might have written it "but a walking shadow, a poor player that struts and frets his hour upon the stage and then is heard no more: it is a tale told by an idiot, full of sound and fury, signifying nothing."