Uncle Sam, I can assure you, is not paying for cancelled trips. Even if you are in Egypt and being evacuated right now, you are signing a waiver agreeing to pay the gov't for your evacuation flight:

"U.S. citizens requesting evacuation will be asked to sign paperwork promising to reimburse the U.S. Government for flight costs at a later date. Exact flight costs are not yet available, but should be comparable to a one-way commercial flight from Egypt to the safe haven location."

Unfortunately, travel insurance may not be much help either. To see statements by some travel insurance providers about the civil unrest in Egypt:
http://blogs.squaremouth.com/travel-...rest-in-egypt/

The best bet might be to ask the airline/s you have booked with if you can rebook at no or little fee for another intermediary destination on your trip from IST to DXB.