Throughout last year’s presidential campaign, Barack Obama lambasted the Bush administration for fighting “the wrong war” in Iraq and ignoring the right one in Afghanistan. Iraq was a “war of choice,” Obama claimed, while Afghanistan was a “war of necessity.” Repeatedly, he claimed that, if elected president, he’d unveil a new “stronger, smarter and comprehensive strategy.” In March, in one of those solemn-looking occasions in which he excels, Obama said that the new strategy, which he did not elaborate, was already in place. He speeded up the troop buildup ordered by the Bush administration, and a few weeks later named...