As Cliff Victor Davis Hansen Jr May notes:
VIETNAM AND IRAQ [Cliff May]
â€œThe only obvious and striking similarity is that the enemy is counting on American public opinion to force a retreat. In fact, Zawahiri noted in his letter that â€˜we are in a battle, and that more than half of this battle is taking place in the battlefield of the media.â€™ Al Qaeda understands that they cannot win on the battlefield against the spirit of determination of America and our Iraqi allies. Prematurely leaving Iraq would have catastrophic consequences â€“ far greater than those we saw in Vietnam â€“ as retreat would, in effect, hand the Iraqi people over to terrorists who have stated their intention and proven their capability to launch horrifying attacks.â€
From a Floor Speech today by U.S. Sen. John Cornyn (R-Texas) chairman of the Emerging Threats and Capabilities Subcommitte
The son of a military officer, Cornyn simultaneously supported the Vietnam war while avoiding it, so that would make two Iraqi/Vietnam similarities for those keeping score at home.