Against who? Some guys in the the Yemeni desert? Saudis have been trying that for years.
Without turning this into a regional, all-out war, how do we respond? Now if something like the USS Cole attack happens it will be out of our hands, we'll have to respond and damn the consequences, but until then we'll probably do things covertly.
"Another"? The US has neither launched nor is it fighting a major regional war now.
If you have some sources talking about how how the US can't launch a regional conflict I'd love to see them.
The two major regional contingency capability (which was not a strategy, but a principal notionally underlying national security strategies for a couple decades) was concocted in 1993 as, basically, political cover for massive defense cuts -- that is, it was saying "despite the cuts, we will retain this capacity" -- and was very quickly recognized as a largely fictitious capability [0] especially as the US fought major regional contingencies after that point and it was clear that it could at most prosecute one effectively and be prepared to engage in a holding action elsewhere [1], even when "major" was much smaller scale than war with Russia or China, and was formally abandoned in 2012.
[0] Part of why this recognition was because the formal documents outlining the concept and how the capacity would be met had caveats which indicated that it wasn't really a capacity to fight two MRCs effectively and simultaneously.
[1] "Win one, hold one" was described as the likely best-case actual capacity years before the overlap of Afghanistan and Iraq conflicts concretely demonstrated the lack of genuine two-MRC capability against much less capable foes than Russia/China.
Maybe this is just their retaliation. This self rightousnes ... as if the us main land was bombed.
Terrorists can not retaliate, at least not rightfully. They can gtfo of Yemen though.