Part of the debate going on within Pakistan is similar to the US conflicts over state's rights versus federal intervention. Seems to me we even fought a civil war over this issue. I don't think Pakistan wants to do that.
The stated goals of the war have not changed since the initial invasion.
The War in Afghanistan, which began on October 7, 2001 as the U.S. military operation Operation Enduring Freedom, was launched by the United States with the United Kingdom in response to the September 11, 2001 attacks. It was the beginning of the dubbed War on Terror. The stated purpose of the invasion was to capture Osama bin Laden, destroy al-Qaeda, and remove the Taliban regime which had provided support and safe harbor to al-Qaeda.
Two military operations in Afghanistan seek to establish control over the country. Operation Enduring Freedom (OEF) is a combat operation involving coalition partners led by the United States against Al Qaeda remnants, primarily in the eastern and southern parts of the country along the Pakistan border. OEF is not a NATO operation, although many coalition partners are NATO members. Approximately 20,000 troops are in OEF, including approximately 18,000 U.S. forces. The second operation is the International Security Assistance Force (ISAF), established by the international community in 2002 to stabilize the country. NATO assumed control of ISAF the following year. By May 2008, ISAF had an estimated 47,000 troops from 40 countries, with NATO members providing the core of the force. The United States has approximately 17,000 troops in ISAF.
Of the goals, only the removal of the Taliban regime has been accomplished, although the thoroughness of that removal has recently been challenged by the resurgence of the Taliban.
Operation Enduring Freedom's job is to destroy al-Qaeda and Osama bin Laden. There has been some success in killing leaders and member of al-Qaeda, but the organization seems to still be functional. Osama bin Laden is assumed to be alive and functioning, although probably not as effectively as he was prior to the invasion of Afghanistan.
Certainly crossing international borders without the permission of the country an armed force is invading is not politically correct. As with any criminal act the actors need to decide if the repercussions are worth the risk.
Split with Pakistan
An unnamed senior Pentagon official told the BBC that at some point between July 12 and September 12, 2008, President Bush issued a classified order to authorize U.S. raids against militants in Pakistan. Pakistan however said it would not allow foreign forces onto its territory and that it would vigorously protect its sovereignty. In September, the Pakistan military stated that it had issued orders to "open fire" on American soldiers who crossed the Pakistan border in pursuit of militant forces. On September 25, 2008 Pakistani troops shot towards ISAF helicopters, which belonged to American troops. This caused confusion and anger in the Pentagon, which asked for a full explanation into the incident, and they denied that American choppers were in Pakistani airspace. Pakistani President Asif Ali Zardari was quick to deny that shots were fired but instead insisted that the Pakistani troops shot flares to warn the Americans that they were in Pakistani airspace. This has added to the doubts that have been expressed by certain Pentagon and Bush Administration officials about the capabilities of the Pakistani Armed Forces to confront the militant threat. This has all added to the split that occurred when American troops apparently landed on Pakistani soil to carry out an operation against militants in the North-West Frontier Province but ‘Pakistan reacted angrily to the action, saying 20 innocent villagers had been killed by US troops’. On October 1, 2008, a suspected U.S. drone fired a missile against militants inside Pakistan’s North-West Frontier Province near the Afghan border. It is believed that six people died in the incident. This is again proof of America’s frustration at the lack or failure of action by the Pakistani side against the militants held up on Pakistani soil. Attacks of such have drawn a stiff response from Islamabad, accusing the United States of violating their airspace.
It seems that President Bush believes that illegal acts against Pakistan are worth the possible repercussions.
To the best of my knowledge the US Congress has not declared war on Pakistan. Pakistan may be angry about our invasions, but they haven't declared war on us for these acts, yet.
Being the bully on the block does have its advantages.