How much IR/radar return would an airship present if constructed/coated with suitable materials? To shoot it down, you have to know it's up there, right? Presumably a big ass Goodyear logo wouldn't be giving it away.
One approach could be to base it at a friendly spot in the Gulf, fly it with the jetstream to the Afstan border then drift eastward over Afstan at 70-80kt and recover to either (a) an airstrip in Pakistan from which it can be flown back or more likely (b) a landing platform outside Pakistani territorial waters which could then shuttle it back to the main base. Some of the many container ships clogging up the harbours near Singapore could be refitted for that role (could also serve in the role of pirate bait)
The tricky part would be avoiding an propulsion failure which would cause overflying Pakistan into Indian airspace...