The Iraq surge provided more troops at a critical time, but a time that was politically opportune. Prime Minister Nouri al-Maliki's new democratic government (only formed in May 2006) was prepared to take counterinsurgent actions (e.g., isolating urban neighborhoods with concrete barriers). The grand message the Bush administration sent, however, was decisive: America will persevere and win.
President Bush didn't give a time line, he set a condition: stability that fostered Iraqi democracy and permitted Iraqi assumption of the battle. That's leadership with spine. Obama has, at least rhetorically, warmed to Iraq's emerging success, and briefly lauded it in his speech, though in his triangulation mode he seeks to segregate Afghanistan from Iraq. It is a compartmentalization that serves Democratic Party politics, just like re-naming the Global War on Terror an "overseas contingency" has "triangulatory" purposes.
The fact is al-Qaida has been in the crosshairs since Sept. 12, 2001. Would that we had begun targeting al-Qaida after its attacks on the World Trade Center in 1993 and our East African embassies in 1998. We didn't. Our actions in what the Clinton administration framed as discrete theaters in fact encouraged al-Qaida's millenarian fanatics.
The Clinton administration's decision to withdraw from Somalia after 1993's Blackhawk Down fiasco is an example of the self-destructive falsehood of that narrow scope. Al-Qaida reached the conclusion that the United States lacked staying power, the will to persevere.
The "Third Letter to the Africa Corps" (a collection of letters, actually, translated in June 2002) substantiates this point. Somalia is judged a "splendid victory" with "profound implications ideologically, politically and psychologically." One letter adds: "The Somali experience confirmed the spurious nature of American power and that it has not recovered from the Vietnam complex. It fears getting bogged down in a real war that would reveal its psychological collapse at the level of personnel and leader(ship)."
Al-Qaida recruited globally, using the Somalia narrative.
This is why McChrystal got his troops. This is also why a condition, not a time line, must guide American military engagement in Afghanistan.