"Political dynamics in Afghanistan can in no way be compared to that which prevails in Pakistan..."
Why is that? What dynamic ruled Pakistan before Zardari? Was that rule by Musharraf before Zardari by electoral consent? ANY electoral consent?
I don't care to drift too far from the topic and have alluded to the Hezb-i-islami party as led by an enemy of Afghanistan, Gulbuddin Hekmatyar, but possessing a member of Karzai's cabinet also and a number of positions within Karzai's government. This, of course, reflects the fracturing of HI back in 1979 that eventually led into three groupings (HIG, HI Maulawi Khalis and, finally, HIA).
"Provide any such links of JUI with those who fight ISAF in Afghanistan...!"
I'd recommend Ahmad Rashid's book Taliban-Militant Islam, Oil And Fundamentalism In Central Asia. You might research that as well.
Here's another that suggest the Madrassas run by JuI are critical to Omar's recruitment of troops-
Mullah Fazl ur Rahman:Taleban Mentor-Mohammad Abbasi Feb. 21, 2010
Oh! And one more-
Hizb-I-Islami Gulbuddin-Institute For The Study Of War
There are, in fact, quite a few allegations suggesting JuI's involvement with a number of these groups but something tells me you'd eithere dismiss them in some cases while supporting such in others. No matter.