The official told The Associated Press that Bush signed the order over the summer. It gives new authority to U.S. special operations forces to target suspected terrorists in the dangerous area along the Afghanistan border.
In addition to the presidential approval for special operations missions, conventional ground troops have new authority to pursue militants across the Afghan border. The "rules of engagement" have been loosened, allowing troops to conduct border attacks without being fired on first if they witness attacks coming from the region. That would include artillery, rockets and mortar fire from the Pakistan side of the border.
The Pakistani government is not told about the targets in advance because of concerns that the Pakistani intelligence service and military are infiltrated by al-Qaida and Taliban supporters, the former official said.
U.S. counterterror operations along the border are highly unpopular in Pakistan, whose new leadership is trying hard to show independence from Washington.
At the same time, the former official said, the Pakistan government recognizes that its settled areas are increasingly targeted by terrorist and militant attacks emanating from the tribal region and its military is not equipped to counter the threat.