It was, of course, a sign of things to come, a larger, darker reality in which partisan affiliation and political expedience would threaten to blot o… - Barack Obama

Now, those who were killed and injured here were gunned down by a single killer with a powerful assault weapon. The motives of this killer may have been different than the mass shooters in Aurora or Newtown. But the instruments of death were so similar. And now another 49 innocent people are dead; another 53 are injured; some are still fighting for their lives; some will have wounds that will last a lifetime. We can’t anticipate or catch every single deranged person that may wish to do harm to his neighbors or his friends or his coworkers or strangers. But we can do something about the amount of damage that they do. Unfortunately, our politics have conspired to make it as easy as possible for a terrorist or just a disturbed individual like those in Aurora and Newtown to buy extraordinarily powerful weapons, and they can do so legally.

America is big enough to accommodate all their dreams.

But how can we in good conscience justify war before we’ve tested a diplomatic agreement that achieves our objectives; that has been agreed to by Iran; that is supported by the rest of the world; and that preserves our options if the deal falls short? How could we justify that to our troops? How could we justify that to the world or to future generations? In the end, that should be a lesson that we’ve learned from over a decade of war. On the front end, ask tough questions. Subject our own assumptions to evidence and analysis. Resist the conventional wisdom and the drumbeat of war. Worry less about being labeled weak; worry more about getting it right.