President Barack Obama's speech in Cairo on relations between the West and the Muslim world was a tour de force. Watch it; read it. (My colleague Nick Baumann lists the nine hard truths in the speech.) But this episode is a reminder that a speech is composed of two elements: the words and the person delivering them. Look at this portion of the address:

Now, make no mistake:  We do not want to keep our troops in Afghanistan.  We see no military -- we seek no military bases there.  It is agonizing for America to lose our young men and women.  It is costly and politically difficult to continue this conflict.  We would gladly bring every single one of our troops home if we could be confident that there were not violent extremists in Afghanistan and now Pakistan determined to kill as many Americans as they possibly can.  But that is not yet the case.

...Today, America has a dual responsibility:  to help Iraq forge a better future -- and to leave Iraq to Iraqis.  And I have made it clear to the Iraqi people -- (applause) -- I have made it clear to the Iraqi people that we pursue no bases, and no claim on their territory or resources

It is not hard to imagine George W. Bush, as president, saying those same words. Yet millions of people at home and abroad would not have believed his claim to have no interest in sustaining a US military presence in Afghanistan, Iraq or anywhere else. Why? Well, if you don't know, you slept through the first eight years of this century. The fine words that Bush did frequently speak about promoting democracy abroad and protecting the world from tyrants and terrorists were undermined by his misrepresentations of the actual threats (see WMDs in Iraq) and his actions (see rushing to war in Iraq when the UN weapons inspections process was under way and working).

Obama has no such baggage. More important, he is willing to acknowledge US errors: