Actually, I believe that as long as Afghanistan is stable and has no spillover effect in Russia, the Russians don't care how Pakistan goes about their strategy of fixing Afghanistan. Russian interests in Afghan only go as far as making sure that Russia doesn't ever have to intervene in the country. This is why Pakistan is becoming increasingly important to Moscow. The Russians realize that Pakistan will be the dominant player in Afghanistan, and they want to make sure that the great game being play is in Russia's favor.
From Islamabad's perspective, it has both everything to gain and everything to lose. Pakistan cannot risk another civil war in Afghanistan, so it has no choice but to help Kabul to broker some sort of peace deal between the Taliban and the government. This is especially true since it cannot afford to bring in more refugees, and the risk of a civil war might embolden the militants on Pakistan's side of the border.
Basically, what I'm saying is, shits gonna hit the fan, yo! And only Pakistan can fix it.