Vital supplies for U.S. troops in Afghanistan -- food, fuel and ammunition -- are being blocked in the Khyber Pass. The main supply route has been closed by Pakistan after a U.S. air strike killed two dozen Pakistani troops, apparently by accident.
Pakistan is critical to U.S. success in Afghanistan but relations as of now have never been worse.
CBS News correspondent Mandy Clark reports that at the border near the site of the incident, anger is still boiling over.
The images of those killed enraged the people of Pakistan. Every major city saw protests against the United States. Some burned an effigy of President Barack Obama, others chanted "Death to America."
"We need to announce a holy war with U.S.," one Pakistani man said.
Pakistan is still angry about the Navy SEALs raid that killed Osama Bin Laden, and American officials have often accused Islamabad of providing insurgents with safe havens from which they launch attacks across the border on U.S. troops.
As the bodies of Pakistani troops were buried, Pakistan's government retaliated by closing the border to NATO trucks heading to Afghanistan, carrying 40 percent of supplies to U.S. bases.
Closing the border is one of the few ways that Pakistan can show its anger at the U.S. for the NATO airstrikes, and goes some way to appease the rising anti-American sentiment in the country.
On Monday, there were thousands of trucks stranded on the Pakistani side of the border. Truckers told CBS News they were afraid of being attacked while idling.
NATO has promised an immediate investigation, but the anger over this incident has dashed any hope that the U.S. and Pakistan will repair relations anytime soon.
Besides closing the border, the Pakistanis are giving the CIA 15 days to shut down drone operations from a Pakistani air base in the south.
CBS News correspondent David Martin reports that while the border closing will make things difficult, U.S. officials say supplies already stockpiled in Afghanistan, in addition to routes coming in from the north and by air, can make up the difference.
The facts of the cross border firefight remain in dispute but there is no doubting the fresh wave of anti-Americanism it has triggered.
The State Department had to warn Americans in Pakistan they could be targets of retaliation.
General James Mattis, the commander of the U.S. Central Command -- which oversees operations in Afghanistan -- ordered an investigation into what everyone agrees is a major setback in an already rocky relationship.
According to U.S. officials, it began when a patrol of American Special Forces and Afghan troops took fire from the direction of two Pakistani military outposts. Pakistani officials insist the two outposts, located on a ridge 300 yards from the border, did not fire first. The Americans called in helicopter gunships which attacked the two outposts. The Pakistani troops shot back and the ensuing firefight lasted nearly two hours, despite what a Pakistani official says were repeated appeals to stop.
It was the worst but not the first cross border firefight. Shelling of American outposts from positions inside Pakistan has quadrupled this year. Most of it is by insurgents but in some cases it has come from locations very close to Pakistani outposts.
The Americans thought they were firing on insurgents, but the U.S. and Pakistan have worked out procedures to guard against cases of mistaken identity and those procedures failed disastrously.
11/29/11 Editor's note: The cell phone video included in this report on the aftermath of the US-airstrike that occurred on the Pakistan/Afghanistan border Nov. 26 has been removed. While the report is accurate, the accompanying cell phone footage was related to another incident in the region.