The reasons have as much to do with geography as they do politics.
Afghanistan is vital not only because the US needs to continue to deny al Qaeda a breeding ground in the country that played host to al Qaeda in the runup to the 9/11 attacks, but because it is adjacent to the current breeding grounds for al Qaeda and its affiliated terror groups in Pakistan.
Details of the pact have yet to be released. But over the past year, top generals and Pentagon officials have sketched — in congressional testimony, interviews and forum discussions — an outline of how the U.S. will operate after the accord takes effect, following the departure of most U.S. troops in 2014. U.S. and Afghan troops will live together on joint bases formally operated by the Afghans. The U.S. mission for training Afghan soldiers and police will continue until 2017 or so, although for financial reasons, the size of those Afghan troops under U.S. mentorship will shrink after 2014. Starting immediately, Afghans will have significant if incomplete influence over U.S. commando raids.That's right.
But these mentorship missions will not be the most important ones the U.S. executes in Afghanistan after 2014. They’re merely the visible ones. And they’re the cost of getting to the missions the U.S. considers most important.
To be blunt: Afghanistan is valuable to the United States because it’s the most logical place from which to conduct a war in Pakistan that’s primarily fought by armed drones and occasionally special operations forces. It’s not really valuable in and of itself. The U.S. interests in Afghanistan, as defined by the Obama administration, are to keep Afghanistan from internal collapse so al-Qaida doesn’t return. President Hamid Karzai’s government is corrupt? Yawn. Dealing with that is an expensive diversion from the core issue.
The core issue, as the Obama team sees it, is that there’s a residual al-Qaida presence next door, in the Pakistani tribal areas. Because Pakistan won’t let U.S. troops overtly operate on its territory, the U.S. basically needs to rent some nearby property. Afghanistan doesn’t have much to offer the rest of the world — minerals, maybe? — but it has a lot of land abutting Pakistan.
It's about maintaining forces close to Pakistani territory. Pakistan, which is nominally a US ally in the war on terror is itself the territory targeted with this deal so that the US can continue to target and eliminate al Qaeda and affiliated terrorists in the frontier provinces that Pakistan's government lacks the ability to contain.
The frontier provinces, including the NWFP and Waziristan, are a hotbed of terrorist activities, and cross-border attacks are all too common. Pakistan maintains nominal control over the territories, which operates autonomously and when Pakistan has sent in military forces to quell the terrorist activities, they've gotten savaged.
In the past three years, the frontier provinces have been increasingly targeted by American UAV airstrikes - hitting high value targets and tracking down links between various terrorists operating there, including the Mehsud clan and Haqqani network.
Those raids, along with the successful raid to eliminate Osama bin Laden, have caused tremendous friction between the US and Pakistani government and the Pakistani intelligence service (ISI). The Administration appears to be accepting the fact that relations with Pakistan will continue to be rocky, but there may be a tacit deal in place to allow the US to use Afghanistan as a staging area for its UAV strikes to go after targets that Pakistan deems inconvenient - the Islamic terror groups like al Qaeda and those other terror groups. Such a deal would give the Pakistani government the maneuvering space to decry UAV airstrikes, but give silent assent to those successful strikes that eliminate threats to Pakistani security as well. After all, the Haqqani network is as much a threat to Pakistan's government as it is to Afghanistan (or the US).