Foreign policy of Pakistan
9/11 altered the global order considerably. Many of the word states modified their foreign policies. Pakistan was no exception in this regard. Being on the crossroads of the territories where War on Terror was ignited, Pakistan needed to reform its foreign policy particularly in context of the US and Afghanistan.

Post 9/11 Foreign Policy of Pakistan
According to the United States, 9/11 was the catastrophic event engineered by Afghanistan based Al-Qaeda. This militant wing was led by Osama Bin Laden who was the host of Afghan Taliban government in 2001.
At the refusal of Afghan Taliban to hand over Bin Laden to the US, the then President Bush launched a US-led international alliance against terrorism and invaded Afghanistan.

Pakistan being neighbor and an important strategic location in terms of the War on Terror brought up following major changes in its foreign policy;
Pakistan's post 9/11 foreign policy no more remained India-centric. Now the events in the US and Afghanistan carried much of influence on its foreign policy making.
Pakistan's post 9/11 foreign policy made the country a front line ally of the US in war on terror. In this wake though Pakistan did not send its troop to fight in Afghanistan but it had to provide its land routes, some air and military bases in order to assist the NATO forces.
Pakistan's foreign policy had to bring a change in dealing with the Afghan government of Taliban. Previously, Pakistan was a favorable country to the Afghan Taliban government that came into power in 1996. But at the turn of the events the Taliban government lacked support from Pakistan.
Post 9/11 foreign policy of Pakistan brought the country into the bloc of the US, keeping it disengaged with Russia and other Eastern powers. The relations with China, however, remained warm.
Pakistan in Regional and Global Politics
Amid the scenario when the War on Terror is in its last phases in Afghanistan, Pakistan is once again reforming its foreign policy to exploit the regional and global politics into its national interest. In future, Pakistan has following prospects in regional and global politics;
Pakistan being the host of China Pakistan Economic Corridor is going to gain economic and trade importance in the region.
Pakistan has long experience of combating terrorism. This makes the country an experienced and steadfast state in the region. Pakistan can share its experience with other Asian countries to help them make peace.
Pakistan is of great importance in the region for helping the Middle Eastern countries to be out of the chaos. In this wake, Pakistan made a diplomatic comeback while trying to calm the tensions between Iran and Saudi Arabia.
Pakistan is still important in global politics as it will help the US troops to seek a safe exit from Afghanistan.
Globally Pakistan has sought appreciation for its fight against militancy. This will keep it engaged with the global powers which can help to develop the country by sharing modern technology and education.

Conclusion
Pakistan altered its foreign policy to cope with the post 9/11 foreign policy and it is altering it now to manage well in the regional and global politics.

A very comprehensive approach to tackle the question.. please keep covering questions this way it is quite helpful.

@Sahal,
A well researched and detail-oriented approach to the topic at hand.
Keep doing your best efforts.
Many thanks for bringing your research to the forum.

Best.