The US is upset because Pakistan wants to defend its borders against US raids. How would they feel themselves if for example the Mexican military would make raids across the border to the US at will? Wouldn't they shoot back?

http://www.foxnews.com/story/0,2933,423104,00.html

Report: Top U.S. Military Officer in Pakistan on Unannounced Visit With Senior Leaders

Tuesday, September 16, 2008

ISLAMABAD, Pakistan — Top U.S. Military Officer Adm. Mike Mullen flew to Pakistan Tuesday for an unannounced visit with senior leaders amid Pakistani orders to fire on U.S. troops conducting cross-border raids from Afghanistan, FOX News confirmed.

"The chairman is in Pakistan today for meetings with senior civilian and military leaders," Navy Capt. John Kirby, spokesman for the chairman of the U.S. Joint Chiefs of Staff, told Reuters.

The Pakistan's military ordered its forces Tuesday to take the offensive if U.S. troops launch another air or ground raid across the Afghan border, an army spokesman said Tuesday.

The orders, which come in response to a highly unusual Sept. 3 ground attack by U.S. commandos, are certain to heighten tensions between Washington and a key ally against terrorism. Although the ground attack was rare, there have been repeated reports of U.S. drone aircraft striking militant targets, most recently on Sept. 12.

Pakistani officials warn that stepped-up cross-border raids will accomplish little while fueling violent religious extremism in nuclear-armed Pakistan. Some complain that the country is a scapegoat for the failure to stabilize Afghanistan.