I don't think that his war will have as much impact as people think that it will. Firstly, with the last gulf war, Iraq was producing large amounts of oil. This meant that when Sadam lit all of the wells on fire oil prices around the world went through the roof, if this wasn't bad enoungh for the airlines the passengers stopped flying because of the terrorist threats.
This time around the world is entirely different, Iraq no longer produces any of the worlds oil as the UN sanctions do not allow it, so although the destabilisation in the region may lead to some higher prices it will be no where as much as last time. Also after september 11 the airlines are already at the bottom of the trough so there will not be as effected as last time when they were all enjoing good times. Lets not forget as well that passengers now live with the fear of terrorism permenantly thanks to Bin Laden, so I feel there will not be such a big drop in passenger numbers as before.
As stated before, it will be better for all concerned if the conflict is swift or even better doesn't happen at all (this is very unlikley). Airlines will not hire new crews whilst the conflict runs, but they will not be making anyone redundant as they are already lean after the 9/11 attacks. Once conflict is over recruiting will start fairly quickly.