WASHINGTON -- Giving little relief to those skeptical of U.S. involvement in Syria’s civil war, President Barack Obama on Monday said he understands the dangers of mission creep and was determined to avoid them.

Obama, in a taped interview with PBS’s Charlie Rose, defended his decision to provide weaponry to Syrian rebels, saying it followed careful and comprehensive deliberation. His policy, he added, is meant to strike the right balance and is not open-ended.

It is very easy to slip-slide your way into deeper and deeper commitments because if it's not working immediately, then what ends up happening is six months from now people say, 'Well, you gave the heavy artillery.