India, March 29 -- Dear Reader,

Three hours after we take off from London, the plane begins to lurch. At first, I don't notice; I am half asleep. Then the seat belt sign flashes on.

I look around at the darkened cabin and am seized with a sudden dread-are we flying over Iran? This war feels as if it is closing in, everything from gas shortages to scary stories from people close to the hostilities, like a colleague from Dubai telling us about the fighter planes that escorted his commercial aircraft out of the airport, or another showing us pictures of drone battles shot with his phone.

All day I have been reading Black Wave, a history of the West Asia since 1979. At 35,000 feet, somewhere over the region it describes, it stops feeling l...