The details of what happened are hazy, but this much we do know: on 9-11-2012, four Americans were killed in Benghazi, and one of them was John Christopher Stevens, a career foreign service officer and our ambassador to Libya. Stevens is the first American ambassador to die in service in the last twenty years, and his death and the violence that surrounds it have had a striking political effect, internationally and domestically.

Although at first the assault on the American consulate seemed ad hoc and therefore much like the violence against the US embassy in Cairo, many observers now think that the attack in Benghazi was a planned operation. In Cairo, a mob, incensed at the depiction of Mohammed in an obscure American polemical film, stormed the embassy and entered its grounds, but there was no attack on American citizens. But it is difficult to tell what actually happened in Benghazi. One report is that Stevens and the other casualties were in a vehicle trying to leave the consulate amid a demonstration, and the vehicle was hit by a rocket-propelled grenade. Another source reported that Stevens was alive when he was brought to a hospital by Libyan police or soldiers, and that he had no wounds but instead died of asphyxia or smoke inhalation. Some say that he was killed by Qaddafi sympathizers. Others say that he was killed by Salafists or their allies. Whatever really happened, one major result of the dreadful event is that President Obama, who had secured the political campaign's national security high ground, must now play a little defense.

Obama and Romney have traded sharp barbs about the incident, with Romney's saying the mess is Obama's legacy of weakness and the president's castigating his opponent for using the tragedy to gain political advantage. But an American presidential campaign is, we regret, a blood sport. President Obama has already said that we will respond decisively in some way, but that is a promise based only on the expectation created by his success in getting bin Laden. Meanwhile, Romney will nip at his heels.

Neither political convention was interesting, and each succeeded only to squander as much public money as possible on a social event to celebrate a process that has been fundamentally altered by money itself. But during and after the convention, although Romney castigated Obama for many things, it was interesting that he said nothing about Obama's handling of national security, and for a couple of good reasons. For one thing, many of Romney's defense views are not diametrically opposed to Obama's. Romney is a pragmatist who could be expected to continue such policies as the campaign to bomb enemies in Pakistan, Yemen and elsewhere, while permitting---or even accelerating---the withdrawal of American forces from Afghanistan. For another, until the the mess yesterday, the view of most Americans has been that Obama has actually done relatively well in national security. The most recent polls, in an historic reversal, say that, while the Republican will be better with the economy, it's the Democrat who is more adept at national security. A large part of this, of course, is a function of the killing of Osama bin Laden.

But all this has changed, at least for now, with the breach of American soil in Cairo and the murder of Ambassador Stevens. The most likely event is that the situations in Libya, Syria, Iraq and Afghanistan (and perhaps even Egypt) will deteriorate between now and election day, and Romney will say that the chaos demonstrates Obama's naivete, ineptitude and lack of fortitude. The chips that Obama has amassed from his policies of surge, withdrawal and assassination will be lost in the aftermath of the Arab Spring, the unintended consequence of encouraging republican democracy among people with a taste for something completely different.