1) It would also depend if going in would create more instability in the country and hence long term create more terrorists.

2) If the countries leadership are using the terrorists as puppets to further their own aims then it would be a different scenario.

I think Iraq and Lebanon are from item number 1. Iran might be proxing terrorist but they are being used from another nation, also it is hard to pin the blame on them. After all selling munitions is hardly the same as pulling the trigger. I would however make it a capital offence to sell WMD to NGO's be they Hezbollah or the Red Cross or Reuters or FOX or anyone else who is not a stable government.