The California Republican said while the military surge in Afghanistan has pushed back the Taliban in the past year, further disrupted al-Qaida, trained thousands of Afghan security forces, and cleared the way for many civilians to return to school and work, Obama has hindered the prospects for lasting success by laying out a timetable for withdrawal.
"These decisions by the president have made it increasingly difficult to build up trust and confidence with the Afghan institutions that will ultimately ensure that the security and political gains by U.S. and NATO efforts are sustained into the future," McKeon said. "Moreover, with our eyes at the exits, I'm uncertain whether we will be able to achieve the key tenets of the president's own strategy due to the constraints that the president himself has put in place."
McKeon said "in the absence of sustained public opinion to support the mission in Afghanistan, from the White House on down, many have begun to question what we're fighting for."
Rep. Adam Smith, D-Wash., the ranking minority member on the panel, said he agreed with McKeon there has been "enormous progress" in giving the Afghan government and people "the chance to have a stable and lasting government."
But, he said, Afghanistan's history of war, poverty and ongoing insurgency make it "a very difficult country."
"We are much further along the road to achieving that goal now than we were two years ago, and that's due in large part to the efforts of our troops, and we must thank them for that.
"But the bottom line is, we are not going to stay there forever. I don't think anybody would say that we should. And if we're not going to stay there forever then we need a plan to leave and to leave responsibly, and that's what was first put in place by the president in 2009 and then solidified at the Lisbon conference in 2010 with NATO. We have what I think is a realistic plan."
James Miller, the defense undersecretary for policy, told the panel that "while we have faced serious challenges, our strategy is succeeding."
Miller said the recent Koran-burning incident and the killing of 16 Afghan civilians were serious setbacks to U.S.-Afghan relations.
"But it is critical that these tragic occurrences not blind us to the significant progress we have made," he said.
"Achieving a durable peace in Afghanistan will require some form of reconciliation among Afghans," Miller said. "It is by no means certain that this effort will bear fruit in the near term, but it is very much in our national security interest to try.
"Success in Afghanistan will depend on the support of ... Afghanistan's neighbors, particularly Pakistan."
Marine Gen. John Allen, commander of the International Security Assistance Force and commander of U.S. forces in Afghanistan, said he could tell the lawmakers three things "unequivocally":
"First, we remain on-track to ensure that Afghanistan will no longer be a safe haven for al-Qaida and will no longer be terrorized by the Taliban.
"Second, as a coalition, the largest in recent history, we are well aware and well along on the progress to meet our 2010 Lisbon commitments to transition security lead to the Afghan national security forces by December 2014.
"And third, our troops know the difference that they're making every day. They know it and the enemy feels it every day."
Allen said before the end of the year he intends to provide Obama with a series of recommendations "on the kind of combat power that I will need for 2013 and 2014."
Asked by McKeon if the administration has assured him he will have the forces he needs through the end of the 2013 fighting season, Allen responded: "I have been given assurances by the White House that we're in a strategic conversation, chairman. There has been no number mentioned."
The general said he is "very pleased, frankly, with where we are in that conversation now, sir."
Asked by McKeon, if the White House has always followed his best military judgment, Allen responded, "As the commander in Afghanistan, it has, sir."