Ending a bitter seven-month standoff, Secretary of State Hillary Rodham Clinton apologized to Pakistan on Tuesday for the killing of 24 Pakistani troops last fall and won in return the reopening of critical NATO supply lines into Afghanistan. The agreement could save the U.S. hundreds of millions of dollars in war costs.

Resolution of the dispute also bandages a relationship with Pakistan that will be crucial in stabilizing the region. The ties have been torn in the past year and a half by everything from a CIA contractor who killed two Pakistanis to the unilateral U.S. raid on Osama bin Laden's Pakistan compound.

But the accord carries risks for both governments — threatening to make Pakistan's already fragile civilian leadership look weak and subservient to the United States while offering fodder to Republicans, including presidential candidate Mitt Romney, who contend that President Barack Obama says "sorry" too easily.