Jimmy Carter -- (Meet the Press, MSNBC)

FMR. PRES. CARTER: -- As one of the most troublesome and, and important errors ever made in international policy of the United States of America, for more than one reason. One is that we abandoned a justifiable and major presence in Afghanistan, where we could have helped wipe out al-Qaeda, we might have caught Osama bin Laden. And if not, if he had still escaped, we could have used our tremendous influence at the end of that war, with the Taliban overthrown, to rebuild Afghanistan, and to let them know that the Western world—and the Arab world—were supporting their move toward democracy with full restoration of their basic quality of life. That’s one thing. -- We abandoned that in the middle of what I consider to be a justifiable war, and, and moved our resources, financial resources, our military resources, into Iraq, lost the support of almost unanimous support around the world following September 11, and almost acted unilaterally, with Great Britain by our side, in an unjustified war in Iraq, and alienated a lot of people who would otherwise have been allies with ours.