from what ive been reading, its not really the ICBMs they are worried about.. they are worried that they could put one in a van, and drive it into SK and detonate it... they are also worried about them putting "dirty" ones in artillery shells...
ive also read that China is the one that wrote up all this new sanctions stuff basically... then the UN passed it...
they couldnt hit us if they wanted to, we have missile bases there, and in Alaska as well... i wouldnt be suprised in the slightest if there were more along the west coast that people dont know about, or there are portable platforms ready at any given second...
Japan and South Korea on the other hand, should worry IMO, and worry deeply...
Japan and S. Korea both have Patriot Batterys with Pac 3 missiles. Japan has Aegis equipped warships with the
SM-2/SM-3 missile. The Aegis system has been extremely effective. Around the S. Korean Peninsula there are even more Aegis Warships.
If tensions got worse, im sure we would be sending a THAAD battery or two over to S. Korea. Infact, I'm sure they are already on there way, or are already there...
As far as CONUS, we have GBI (Ground Based Interceptors) at Fort Greely, AK and also at Vandenberg AFB In Cali. GBI attempts to intercept the missile in space and thats are first line of defense besides taking the ICBM out beforehand on the launch pad/underground in storage. THAAD and Aegis attempt to intercept as its coming into earth and the Patriot Pac 3 system attempts a intercept as a last ditch effort seconds before impact.
Patriot Pac 3, Aegis SM-2/SM-3 and THAAD have proven to be reliable and all have a very high success rate at intercepting ballistic missiles. Dealing with a few ICBM's is what are nations ABM system was built around. Dealing with a full on nuclear war it is not. Russia and the U.S both have nukes with MIRV (Multiple Independtly Targetable Reentry Vehicles): It can have up to 12 separate warheads in the 100-300 kiloton range, chaffs and decoy balloons that mimic a warhead.
If N. Korea launched a nuke, theyd be sent back to the stone age. Besides Iran, they are the only ones dumb enough to try it.