had an interesting experience a few years back, flying Swissair to Bombay overnight.
The cabin crew had insisted we pull down the blinds, but a bit later I lifted mine. As we crossed the border into Iran an F-14 passed directly over our starboard wing, in the reverse direction. At a best guess 20 feet above, 70 feet away from the fuselage. The Swissair pilot didn't flinch and our flight continued with no change in direction.
Next morning as we left I asked one of the pilots about it. He totally denied it had happened