just a few comments from my side to this matter:
1.) I don't think US will be able to bomb the Afghanistan (or similar countries) ... b/c with "small" range bombs they won't get most of the Afghanistan, but with "large" range bombs, they will hit also nearby countries
And many terrorists are not even in "terrorists" countries probably ...
2.) Somebody said that terrorists are stupid ... I'll have to oppose this ... of course most of the terrorists "soldiers" are not smart ... but most leaders are
very smart ... just look at the level of education of Bin Laden .... he knows what he's doing ....
3.) If US bombs countries that finance terrorism, terrorists will find another way to get goods anyway
4.) I believe that terrorists won't do anything large right now to the US ... maybe only small things (aka suicide bombings) ... so they can get US into haos, and only then do something big
that's it for now ...