With its new "hot-pursuit" policy, America seems ready to risk offending Pakistan in order to track down potential attackers.
The policy - where the US says it reserves the right pursue fleeing Taliban and Al Qaeda fighters from Afghanistan into Pakistan without Pakistan's permission - made public here by a US military spokesman on Friday, comes after an unprecedented attack on US solders a week ago by a Pakistani border guard during a joint US-Pakistani operation.
Both the shooting incident and the policy announcement have set off protests in Pakistan and a flurry of statements by US and Pakistani diplomats aiming to limit the damage to a relationship that American leaders consider "indispensable" to the war on terrorism.
But while both countries say that any US incursion onto Pakistani soil would be rare, both also admit that the policy could radically broaden America's hunt for terrorists along the 800-mile Afghanistan-Pakistan border where Al Qaeda and the Taliban are thought to be regrouping.
"It is a long-standing policy, that if we are pursuing enemy forces, we're not just going to tiptoe and stop right at the border," said Maj. Steve Clutter, spokesman at Bagram Air Base north of Kabul. "We do reserve the right to go after them and pursue them, and that is something that Pakistan is aware of.... In hot pursuit, we're going to chase down the bad guys." Major Clutter said no such pursuits have occurred as of yet.
Back in March, the last time this issue was raised, the US said it might chase Al Qaeda and Taliban fighters into Pakistan in hot pursuit, but Deputy Defense Secretary Paul Wolfowitz said that such action would come under limited circumstances and only with Pakistani consultation. Friday's announcement was the first indication that "hot pursuit" is official US policy.
The announcement comes at a crucial phase for US-Pakistan relations. For President Pervez Musharraf, Pakistan's military ruler, the decision to allow US troops stationed at Pakistani bases to attack a neighboring Islamic country - Taliban-controlled Afghanistan - has brought the applause of American leaders but protests from his own people. Still, for American leaders, there is a growing sense that Mr. Musharraf and Pakistan could be doing much more to rein in terrorists on Pakistani soil. The question now is whether pushing Musharraf harder would bring Pakistan to the brink of open rebellion.
"It's more of a step forward in an old direction," says M. Afzal Niazi, columnist for the Nation newspaper in Lahore. "There has been a steady encroachment of territory and an erosion of sovereignty." Public reaction will "depend on two things: if anyone is killed and the frequency [of incidents]. If it's every two or three months, then it probably won't cause much of a stir. But if it's every two or three days and two or three kilometers into Pakistani territory ... that's another thing."
While American troops come under regular rocket attack - often at night with the attackers fleeing into Pakistan - the shooting incident on Dec. 29 was unusual because the attacker was a uniformed Pakistan border guard.
The incident occurred near the Afghan border town of Shkin as US troops and Pakistani soldiers were preparing to destroy a cache of weapons that Pakistani troops had discovered. According to the US military, a Pakistani border guard approached US troops and was asked to back away. Instead, the border guard crouched down and opened fire, injuring one US soldier. The Pakistani border guard then fled to an abandoned building which American planes later bombed.
The injured US soldier was evacuated and is in stable condition. The rogue border guard survived the air strike and is in Pakistani custody.
Adding to tensions was the fact that the US plane bombed a building in an area that both Afghanistan and Pakistan claim. Pakistani authorities say the building was a religious seminary, or madrassah, and was within its territory. US troops say the building was in an area under Pakistani control but within Afghanistan's recognized territory.
Publicly, Pakistani officials denied that US had either the right or Pakistan's consent to enter its territory. "There is no question of foreign troops coming onto Pakistan soil," said Interior Minister Faisal Saleh Hayat in islamabad.
But privately, Pakistani officials admit that the practice had been quietly allowed as long as the distance was not deep into Pakistani territory and as long as no civilians were killed.
Sunday, Pakistan's foreign minister said that Pakistan would work more closely with the US to avoid a repeat of last week's shooting incident.
"We have decided to increase coordination so that such incidents to don't happen again," said Khursheed Kasuri, though he did not elaborate on the nature of that cooperation.
In the border state of Northwest Frontier Province - now controlled by religious parties that share close ties with the former Taliban government - protest rallies drew thousands of angry Islamists last week. One top political leader, Maulana Samiul Haq, whose religious school nurtured thousands of Taliban members before they went to Afghanistan, called for FBI agents to be hanged publicly if they repeated earlier raids and arrests at homes of suspected Muslim militants.
Another top leader, Qazi Hussein Ahmed, however, said that his party and the coalition government would express their discontent through more legal democratic means, such as passing a resolution in Parliament. "We will be peaceful," he vowed.
• Naeem Jawad contributed to this report from Islamabad. Material from the Associated Press was also used.