IN the search for an American response to the civil war in Syria, the favorite guidebook seems to be our ill-fated adventure in Iraq. We have another brutal Middle East autocrat holding power on behalf of a sectarian minority. We have another dubious cast of opposition factions competing for foreign patronage. We hear some of the same hawks — John McCain, Paul Wolfowitz — exhorting us to intervene, countered by familiar warnings of “quagmire.” We even have murky intelligence claims that the regime has used weapons of mass destruction. This time, though, we have a president who, having opposed the costly blunder of Iraq and been vindicated, is holding back. The theme song at the National Security Council is “Won’t Get Fooled Again.” As a rule, I admire President Obama’s cool calculation in foreign policy; it is certainly an improvement over the activist hubris of his predecessor. And frankly I’ve shared his hesitation about Syria, in part because, during an earlier column-writing int