I doubt even two carrier strike groups would be nearly enough, by themselves, to present the North Korean regime with a credible threat of a surprise attack. But the F-22 can be used as a small stealth bomber, and the U.S. probably has 100 or so--five squadrons--available at any time. Each F-22 can carry eight 250 lb. guided bombs ("SDB"} internally, so that they do not make it any easier for radar to detect. These bombs are guided, and they have wings of a sort which allow them to be launched several dozen miles from their targets. They can pierce the several feet of concrete of a hardened aircraft shelter and then explode inside it. If forty F-22's were moved to South Korean bases, the 320 SDB's they could carry would place all of North Korea's front-line aircraft at risk of being destroyed on the ground.
Even 700 or so 250-and-1,000 lb. bombs would not be enough for a surprise attack, though, assuming its purpose was to destroy North Korea's air defenses and ballistic missile capabilities, and possibly to neutralize its nuclear weapons (this last job might also involve special forces). There might be as many as 100 targets, with an average of a dozen or so bombs required for each one. But B-2's, which can carry large loads of both 500 lb. bombs and much heavier ones, could add several hundred more to the mix. Three or four might be moved up to Guam, where they from time to time have been temporarily based. With enough refueling, though, B-2's can hit any target in the world from at their home base in Missouri.
I'm not saying the U.S. may, or should, move these forces because it has already determined to use them. I am not calling for Pearl Harbor, American-style. But the credible threat of an attack which would ruin the opponent's military, and which he knows he could not defend against, is the very thing that sometimes removes the need to use any force at all. I think the U.S. has to give Mr. Kim reason to be afraid rather than defiant, which it so far has not done. The U.S. forces in South Korea, powerful as they are, were designed to prevent a repetition of the 1950 invasion. Since Kim has no such thing in mind anyway, they are no threat to him. Moving a force of the kind I described into position to disarm North Korea by surprise, any night, would give him good reason to be more cautious and compliant.
