Well then what is your argument? And doesn't it rely on the assumption that North Korea, a communist regime, is going to develop? Absent market reforms, North Korea can't develop to a point that they're a threat to the U.S. Not in this universe, anyways.
Most people consider a nuclear capability a "developement", evidently you don't.
Also, why do we need to wait for them to be a threat to "the U.S."? All they need to do is be able to strike at Japan, or South Korea. You know, where plenty of US military are located....not to mention the citizens of those countries whose lives are at stake.
You mean South Korea and Japan who are also both far more developed than North Korea in their own right, and who are both under the protection of the United States?
Nuclear capability is a development, in and of itself, but it's not necessarily impressive. Without the resources to make that development relevant, as in the case of North Korea, it's not threatening.