This link is written by a professional writer, but he makes many of the same points that I have tried to make in the past. Only too often, it seems that those on the Left want Iraq to be another Viet Nam. They ignore the differences including facts, and concentrate on the few similarities that exist. As the article leads off with, Sen. Leahy has already declared defeat, when there is nothing to support his assertion.
The only thing that I would add to the above article is that our lack of consistancy more than anything else contributed to 9-11. Most people cannot even remember the Mayaguez incident, or the surprise in the world when Iran was allowed to continue as a whole country after they seized our embassy. Throw on Desert One, the Marine barracks fiasco in Lebanon, our lack of response when the Marine Colonel was kidnapped and executed Klinghoffer was executed in his wheel chair and shoved overboard, and his killer allowed to live in Baghdad. Not to mention Black Hawk Down, the African embassy bombings and the USS Cole, and we gave everyone in the region the idea that we were a paper tiger, just someone to push around and humiliate.
Simple consistancy is more effective in the long run than violent outbursts at random intervals. For example, the Marine Corps Hymn includes the phrase "From the Halls of Montezuma to the shores of Tripoli." In Tripoli, the Bey had been allowing pirates to capture American shipping in the region. By sending in the Marines, the US demonstrated that we were a force to be considered. It provided for a very long period of stability, which only ended after Viet Nam.
Declaring defeat now, when we are making progress will continue the fine tradition we have demonstrated since 1973. Finishing the job may just prevent the need to ever demonstrate our weakness again.