Most interesting fuel stop I ever had was in the 2004-ish time frame. For some reason that I forget, we were moved onto a China Eastern flight from North America (ORD? LAX?) to Beijing (or maybe Shanghai - it was two decades and many, many miles ago).

The aircraft ran short on fuel, so we landed in China, and I woke up and was ready to get off when the pilot announced we were actually in Harbin, not our destination.

Popping up the window blinds, I saw that the aircraft had stopped out on the apron, and fuel trucks were pulling up. And so were military transport vehicles, which disgorged machine-gun toting soldiers who sprinted off to form a ring around the aircraft. They seemed to be facing outward, which made me feel slightly better, although I still don't know what they were guarding us against.

We weren't on the ground in Harbin all that long, and then shortly thereafter actually arrived at our intended destination. It was the only flight I have ever taken that included armed guards.