Afghan attacks over Koran burning renew debate on U.S. pullout Anti-U.S. protests and other deadly attacks roiling Afghanistan have deepened concern at the Pentagon and White House about the plan to wind down the war by withdrawing U.S. combat troops in close coordination with Afghan security forces, several officials and military officers said. Pentagon officials scrambled Monday to contain the damage, insisting that Defense Secretary Leon E. Panetta and top military commanders had not lost faith in a strategy that envisions a steady U.S. pullout as small teams of military advisors train Afghan army and police forces. Panetta and Army Gen. Martin E. Dempsey, chairman of the Joint Chiefs of Staff, "believe we have achieved significant progress in reversing the Taliban's momentum and in developing the Afghan security forces, and they believe that the fundamentals of our strategy remain sound," said Pentagon spokesman George Little. In private, other officers and U.S. officials said riots and attacks after U.S. personnel threw copies of the Koran into a trash-burning pit at the Bagram military base have renewed a debate at the highest levels of the Obama administration and are expected to affect internal deliberations on the pace of the drawdown. "Too many people are asking, 'Why are we still doing this if the guys you're supposed to be helping keep murdering your soldiers?' " said a senior U.S. general, who spoke on condition of anonymity in sharing internal discussions. Officials said the turmoil was unlikely to derail the U.S. plan to pull out troops while small teams of advisors focus on training Afghan security forces and diplomats pursue peace talks with the Taliban. But mistrust between U.S. and Afghan forces may hamper the training and add to security risks, several officials said. Still, a senior Defense Department official said the anti-American backlash is likely to embolden those in Washington who long have argued that more U.S. troops should leave sooner. "There's no question that this is going to spur debate, and that people who already have fairly dire views will have those reinforced," said the official, who spoke on condition of anonymity because he is not authorized to speak to reporters. The number of U.S. troops is scheduled to drop from 90,000 to 68,000 by September. U.S. commanders in Kabul, the capital, have sought to persuade the White House to slow further withdrawals in hopes of locking in gains before Afghan troops are scheduled to take full control of security by the end of 2014. There were fewer protests Monday, but the violence did not entirely abate. In the eastern city of Jalalabad, nine Afghans were killed when a suicide bomber rammed his vehicle into the heavily guarded gates of an airport used by Afghan and NATO forces, as well as civilian aircraft. A Taliban spokesman was quoted as saying the bombing was revenge for the Koran burning. United Nations officials announced they had ordered international staff to withdraw from U.N. offices in the northern city of Kunduz after rioters sought to overrun the compound Saturday. U.S. officials hope the protests will die down in coming days and that hundreds of military and civilian advisors can return to their jobs in Afghan government ministries in Kabul. Advisors from the U.S., Britain, France and other countries in the North Atlantic Treaty Organization were withdrawn abruptly after two American officers were shot and killed inside the Interior Ministry on Saturday. "I'd be less than honest if I didn't say that things are tense here in Kabul," said Navy Capt. John Kirby, a military spokesman. But I will tell you that it is getting calmer. Marine Corps Gen. John Allen, the top commander of the U.S.-led NATO effort, "is not ready right now to have the advisors go back, but this is temporary," Kirby added. At the White House, Press Secretary Jay Carney called the weekend killings "isolated incidents" and noted that U.S. forces have carried out hundreds of missions with Afghan army and police. Other U.S. officials noted that Afghan security forces have sought to quell the protests and have continued to carry out combat operations, often working with U.S. units. Anthony Cordesman, a military strategist at the Center for Strategic and International Studies, a Washington think tank, said the week's violence raised "questions about the U.S. strategy and the value of continuing with the current approach to the war." But in a written analysis, he argued that the U.S. strategy had "been dying for a long time and for many more reasons than the growing distrust" between the U.S.-led coalition and Afghan leaders, including endemic corruption in President Hamid Karzai's government and Taliban sanctuaries in neighboring Pakistan. Times staff writer Kathleen Hennessey in Washington and special correspondent Aimal Yaqubi in Kabul contributed to this report.