"The errors committed in this war have contributed greatly to American frustrations. There was a failure to recognize the extent of the challenge ahead, even as ambitious plans were being laid starting in late 2001. The Bush administration could have had a blank check and recruits lined up around the block, but instead insisted on taking us into war with a post-Cold War military that is only belatedly being built up. The administration failed to seize control of Iraq with sufficient urgency and, when a complex insurgency was well underway, failed to move with sufficient skill to quell it until late in the day. The greater failure was to not adequately communicate the mission to Americans and to the world. All wars go through evolutions, and it is unrealistic to expect no missteps. In this case, however, they are cited most frequently not as arguments to improve the war effort, but as excuses for abandonment...
The American people have been allowed to believe that getting out of Vietnam was the best thing we did there, and that there was no penalty for cutting our losses. It should not be surprising that so many believe the same of Iraq. Looking past the immediate victims of that historic abandonment, the Soviet Union was emboldened by our show of weakness, invading Afghanistan and triggering a fateful string of events. Iran, seized by Islamic zealots, staged the 1979 hostage crisis to kick off three decades of support for terrorism and a bid for regional domination. In both cases, the belligerents knew we would do nothing about it. Figures like Osama bin Laden, among others, noted this void, and created the circumstances we are currently compelled to address."
Indeed, people forget that, after our withdrawal from Vietnam and its fall to the Communists in 1975, nations such as The Philippines, South Korea, and Singapore talked openly of moving away from the U.S. They wondered if, as an ally, we could be counted on. And does anyone believe that Vietnam did NOT encourage the Soviet leadership to believe that we would have no significant reaction to an invasion of Afghanistan?