That is what I don’t understand... What were the jets supposed to do? Were the pilots or a passenger suspected? What was the purpose of the escort?
To me, the most obvious reason would to have eyes close by outside the plane able to observe if a bomb did go off (rather than simply watching a blip disappear from radar). Another idea that is only wild speculation: would mil aircraft be able to jam cell phone signals and thus prevent remote triggering of the device?
Possible, I suppose...