One of the Democratic senators who voted against President Obama’s Syria strike authorization at the Foreign Relations Committee this week said it was a “close call,” but his concerns outweighed the president’s wishes.

Sen. Chris Murphy, a freshman from Connecticut, told MSNBC, “I totally understand where the president is here.”

“It’s hard to watch what happened in Syria with 1,400 people being killed, 400 children being gassed, and stand by,” he said. “My concern is really two fold. One, I worry that a strike makes the situation on the ground worse in Syria, not better. It’s a chaotic situation to begin with, but if Assad responds with even more ferocious strikes against his own people or against our allies in the region, it’s hard to understand how that makes a situation better.”

“And second, I do think it’s difficult to untie the United States from the situation now that this resolution has passed. It not only authorizes the military strike, but it also commits us to a long-term lethal arming of the rebels,” Murphy continued.

“And I just don’t understand how this doesn’t turn into a long-term civil war, even after Assad falls. And I just don’t think the United States is pretty good at trying to pull the political strings within the Middle East, something that I think we should have learned over the last ten years. Certainly a close call, but in the end, I worry that this could actually degrade the situation on the ground and commit the United States to a engagement that could last a decade.”

The senator said part of the case that Obama made to lawmakers was that it wouldn’t escalate into a wide conflict, that “they are going to have checks in place to make sure that if Assad strikes neighbors that it isn’t going to bring the United States into a much broader conflict.”

“And I understand that he believes that,” Murphy added.

“I just think it’s hard to understand how that would occur if, for instance, Assad was to unleash another chemicals weapons attack, we’d have to respond. If he was to strike Israel, well, yes, maybe Israel has the stuff to be able to respond on its own, but the United States would clearly have to stand behind our allies.”

On the possibility that Obama could proceed with strikes without the approval of Congress, the senator said “there are many of us, frankly, who have had a problem with that.”

“The president also made a case to me that once this international norm has been crossed, who else but the United States can stand up today and try to step in and do something about it?” Murphy continued. “But, ultimately, the combination of those two things in the resolution, even if the president is doing it already on his own, just makes a little bit too big of an engagement for many people here.”