From Augustine, Obama might also have learned this formula:
As a rule just wars are defined as those which avenge injuries, if some nation or state against whom one is waging war has neglected to punish a wrong committed by its citizens.
This brief text, from a commentary on the Book of Joshua (Questions on the Heptateuch, VI.10) was cited as authority by the most influential Christian writers, including Aquinas, for a thousand years after it was written. Strikingly, the formula refers specifically to nations that don't control misdeeds by their private citizens, not to nations that are themselves the aggressor. This can easily be read as a precursor to the key U.S. doctrine articulated by National Security Advisor John Brennan last September: to defend itself from al Qaeda, the United States reserves "the right to take unilateral action if or when other governments are unwilling or unable to take the necessary actions themselves." In other words, the U.S. claims the right to use force in Pakistan and Yemen, even without their governments' consent, if they can't or won't suppress al Qaeda. In a speech last March, Attorney General Eric Holder echoed the "unable or unwilling" doctrine, in the fullest public explanation to date of the Obama administration's legal justification for drone strikes. The doctrine doesn't come directly from Augustine, and scholars disagree about its modern-day pedigree. But if the president truly studied and applied traditional just war theory, he might have believed that the doctrine is supported by Augustine's formula. The doctrine seems like a legitimate corollary of a state's right to defend itself against unjust attacks. But since it carries deadly risks of civilian casualties and escalation, it can only be justified as a last resort.
Far less appealing is the other half of Augustine's formula, that "just wars are defined as those which avenge injuries." By approving wars of punishment, Augustine and Aquinas took a dangerously wrong turn, in effect permitting states to be prosecutor, judge, and executioner in their own cause. Wars of vengeance are immoral and, thankfully, illegal. Under the United Nations Charter, self-defense is the only acceptable basis for states to use force without the consent of the Security Council. To be fair both Brennan and Holder made it clear that they were justifying the use of force against al Qaeda and its allies as self-defense, not punishment. Nevertheless, the desire to punish our enemies through war is never far below the surface. On the anniversary of the killing of Osama bin Laden, President Obama said, "I think that the American people rightly remember what we as a country accomplished in bringing to justice someone who killed over 3,000 of our citizens." Obama's boast is wrongheaded but revealing: to call the killing of bin Laden "bringing him to justice" is to mistake a military operation for an execution, with the president as self-appointed judge and jury. If Obama learned this mistake from Augustine or Aquinas, it would be better if he had never read them.
