We wonder more than a bit over here what the scope of the USA actions will be? One politician said something about 'ending states'. How many of them? For a first guess we can look back at the yearly terrorism report of the USA state department back in April 2001 about which states it considers to harbour terrorists. The report lists seven 'villain countries':

Iran, Irak, Libya, Cuba, Syria, North Korea and Sudan

Are you missing Afghanistan? Yes, but only because it was and is not a recognised state. It gets a dishonourable mention. Listed too are two states that do not actively harbour terrorists but do not take adequate action against them:
Yemen and Palestine

Among this list are extremely unlikely candidates like e.g. North Korea, for several reasons, but it is always good to know what the upper limit is. This list is scaring.

Wolfgang