"We are going to complete this investigation and we're going to take whatever steps are necessary to make sure that something like this doesn't happen again," he said.
Obama said it was important to let the investigation play itself out so the details as to how and why the rampage happened are known before he comments further.
Asked what philosophically separates an act of violence from an act of terrorism, the president said, "I think the questions that we're asking now and we don't have yet complete answers to is, is this an individual who's acting in this way or is it some larger set of actors? You know, what are the motivations? Those are all questions that I think we have to ask ourselves. Until we have these answers buttoned down, I'd rather not comment on it.
Obama has yet to publicly announce his decision on a new way forward in Afghanistan and is deliberating whether to send more U.S. troops there, as the commander on the ground, Gen. Stanley McChrystal, has requested. He will meet again Wednesday with his top national security advisors to discuss the Afghanistan strategy.
Asked what variables would play into his decision-making that would cause him to not just take McChystal's recommendation and implement it, Obama said today that he's talking to a wide variety of people, both commanders and civilians, to get the best possible picture of the situation.
"I've been asking not only Gen. McChrystal, but all of our commanders who are familiar with the situation, as well as our civilian folks on the ground, a lot of questions that, until they're answered, may -- may create a situation in which we resource something based on faulty premises," the president said.
Obama described his deliberative process as making "sure that we have tested all the assumptions that we're making before we send young men and women into harm's way, that if we are sending additional troops, that the prospects of a functioning Afghan government are enhanced, that the prospects of al Qaeda being able to attack the U.S. homeland are reduced."
The president in the last week has visited Dover Air Force Base to participate in the "dignified transfer" of troops killed in Afghansitan, and he has visited with wounded troops at Walter Reed Army Hospital. He said such visits "absolutely" have an impact on his decision-making process because it "reminds me that -- these aren't abstractions. The decisions that we make in this White House have consequences for our long-term security and they also have consequences for the individuals who are being deployed."
He added that "as commander in chief, my job is not to just think in terms of one individual or short-term costs, but also what's required to prevent another 9/11, what's required to make sure that we're not seeing another USS Cole. And, you know, ultimately, when I make a decision, it's going to be based on the over arching view of U.S. national security. But I think I would be making poorer decisions if I didn't have to look into the eyes of a family member who had lost a loved one and tell them how grateful we are as a nation that -- that -- that moment, I think, ensures that I'm making the best possible decisions going forward."