"Bush had the right idea; he just took it to the wrong country. We should have been in Afghanistan and he should have wiped the SOB's out and killed Bin Laden. Instead, several hundred billion dollars later and dead troops, what do we have to show for it?"

But you will note that the topic concerns Pakistan. And Taliban is largely from Pakistan:

"The Taliban movement is headed by Mullah Mohammed Omar. Mullah Omar's original commanders were "a mixture of former small-unit military commanders and Madrasah teachers,"and the rank and file made up mostly of Afghan refugees who had studied at Islamic religious schools in Pakistan. The overwhelming majority of the Taliban movement were ethnic Pashtuns from southern Afghanistan and western Pakistan, along with a smaller number of volunteers from Islamic countries or regions in North Africa, the Middle East and the former Soviet Union. The Taliban received valuable training, supplies and arms from the Pakistani government, particularly the Inter-Services Intelligence (ISI), and many recruits from Madrasahs for Afghan refugees in Pakistan, primarily ones established by the Jamiat Ulema-e-Islam"
http://en.wikipedia.org/wiki/Taliban

So, it not like we defeated the Taliban and they moved to Pakistan, but rather they retreated to Pakistan- and retreated to various parts of Afghanistan
The Taliban and Bid Laden are not the same thing- and Bid Laden isn't the leader of the Taliban, but rather he represent is a faction or group of within it. Though Bid Laden would have wanted to be the leader of the Taliban or be the most prominent and respected leader. And no doubt was and still is considered by some as an important leader- or even the only real leader of the Muslim world.

Pakistan was establish as a Muslim nation, a Muslim nation separated from India. One could make the case that Pakistan the nation became necessary as a result of India's independence from the British. Pakistan is still considered a commonwealth nation:

"The Commonwealth comprises fifty-three of the world's countries, across all six inhabited continents. The members have a combined population of 2.1 billion people, almost a third of the world population, of which 1.17bn live in India and 94% live in Asia and Africa combined. After India, the next-largest Commonwealth countries by population are Pakistan (176 million), Bangladesh (156 m), Nigeria (149 m), and the United Kingdom (61 m). Tuvalu is the smallest member, with only 12,000 people."
http://en.wikipedia.org/wiki/Commonwealth_of_Nations

One should note that Afghanistan is not a commonwealth nation. One should also note Pakistan's population.

In comparison Afghanistan and Iraq population are around 25 million each.
Unlike saying Bin Ladin was an US ally, it is somewhat fair to say that the Taliban were our ally in the war against the Soviet Union. But More precisely, the US lifted it's prohibition against providing certain types of military aid and it considered it a priority to provide arms and expertise to whoever was opposing the Soviet military operations- which btw, were slaughtering Afghan resistance and citizens in general to their unlawful occupation.
So the US changed it's policy and agreed to provide some kinds of modern weapons to defeat an enemy who had modern weapons. But the US did not [nor did Pakistan {a commonwealth nation}] want to get into a hot war with the Soviet Union and therefore if they wanted to be involved, needed to use proxies [and therefore any US soldiers involved weren't legally US soldiers- but "special ops/observers/or whatever".