I don't understand this at all.
You're chip leader, it's minimal cost to see a flop with what could end up being a nut hand, very cheaply. The worst that can happen pre-flop is that the BB raises everybody else in which case you've lost a few thousand chips. So I call.
There are two opponents to worry about and only one of them can have the last ace. It seems to me, as I explained elsewhere, that the guy who's gone all in would be very unlikely to have AJ or JJ. I can't see why he would want to close me out if he did so the worry is the first to act. He's covered by the all in anyway. If he puts all his chips in too, he's probably got the best hand but you still get the remainder of the second guy's chips, leaving you almost square.
The all-in may have AQ - again I think AK unlikely because of his pre-flop call.