Yon is being simplistic about the Afghan - good / Pak - bad view. From the Pak perspective, Afghanistan has never accepted the Durand Line (their current border), not even Karzai accepts it. In the 1970s the Afghanis were downright inciting Pashtun nationalism and separatism in Pakistan's border provinces. Add to this the extremely strong pro-India tilt of the Karzai regime and the huge presence India is building there -- lots of investment, huge "consular staffs" despite almost zero tourism, etc -- and there are reasons a rational, national security-minded Pakistani might not wish the current government of Afghanistan well. That this leads those Paks to deal with the devils in the Taliban is probably short-sighted, but there are practical reasons for it, not just that they are evil jihadis vs our white-hatted good guys.