But the damage is probably inevitable. Pulling no punches, Karzai called the shooting an "assassination" and "an intentional killing of innocent civilians" that could not be forgiven.
For their part, U.S. officials pointedly noted that the suspect would be tried under U.S. law, a fine point perhaps made to head off any demands by Karzai that Afghanistan be given custody of the soldier.
The tension could be enough to raise a key question among Obama's top advisers as they stare down this fall's bid for re-election: Should Obama press NATO to speed up its scheduled transfer of security responsibility to the Afghan government at the end of 2014?
Panetta has already said he hopes Afghans will assume the lead combat role across the country by mid-2013, with U.S. and other NATO troops remaining in smaller numbers to perform numerous support missions. U.S. and Afghan officials have said they want a strategic partnership agreement signed by the time a NATO summit convenes in Chicago in May.
Further complicating the matter is the limited patience many of Obama's top supporters have for Karzai.
"The great weakness in Afghanistan is Karzai," said Sen. Chuck Schumer, D-N.Y. "Nobody seems to trust him or like him. And the idea of turning it over to the Afghan forces is the right way to go, but that's a major question mark: Karzai."
Sen. John McCain, the top Republican on the Senate Armed Services Committee, pleaded for public patience on the war.
"I understand the frustration, and I understand the anger and the sorrow," McCain said. "I also understand and we should not forget that the attacks on the United States of America on 9/11 originated in Afghanistan. And if Afghanistan dissolves into a situation where the Taliban were able to take over a chaotic situation, it could easily return to an al-Qaida base for attacks on the United States of America."
Sen. Lindsay Graham, R-S.C., said a primary problem is leaving the country vulnerable and signaling to Iran that the U.S. wasn't committed to the region.
"We can win this thing. We can get it right," Graham said.
Reid spoke on CNN's "State of the Union." Graham and Schumer spoke on ABC News "This Week." McCain spoke on "Fox News Sunday."
EDITOR'S NOTE — Anne Flaherty and Lolita C. Baldor cover military affairs for the AP.
Associated Press Intelligence Writer Kimberly Dozier and AP writers Michele Salcedo and Kevin Freking contributed to this report.
An AP News Analysis
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