Perhaps but troop strength was sufficient for defense and even for offense..it is not suitable for long term occupation and nation building but that is nobody's fault since that is not it's primary purpose, thus Clinton shouldn't get the blame for the misuse of the military.
This is a special forces/intel war from now on. It matters very little how many people we send into Iraq if we don't seal their borders (and our own for that matter) and establish a viable intel network. All of that matters even less in an increasingly hostile environment where we cannot distinguish friend from foe (can you say Viet Nam?).
Terrorism has a lengthy history of humbling mighty armies..especially if those armies have to play by the rules which we are expected to. The Viet Cong and their "policy of harrassment" as opposed to open engagment is just an example. Add to that religious fervor and a situation that can be easily be interpreted as Western occupation by the locals and viola, you have an increasingly uphill "challenge" if you will.