[Jtsummers]

Part of that deployment strategy shift began in the 90s during operations Northern and Southern Watch. Along with a set of shorter conflicts (with NATO and others) under Clinton. There was a political need/desire to shift the way we acted, and it persisted even during the '00s and '10s period of sustained, long-term military conflict.

EDIT: My experience was with the USAF side, other forces still had longer deployment periods at that time, and it wasn't uniform across USAF.

[remarkEon]

Yes that's totally true, though I'll submit that the "deployment cycle" mindset was certainly solidified in the last decade as "the way we do things" - at least on my side in the Army (Obviously I don't speak for everyone, and I know I'm not the only one who had problems with the "cycle" mindset). The politics are also a reason we moved toward that strategy. I just don't think it's a wise one. It probably wasn't wise back then, and I definitely don't think it's wise for the future.

Edit: One of the stories (Myths?) you hear about McChrystal is that he'd ask Company Commanders downrange this question: "What would you do different if you couldn't come home until we'd won?" Granted, that presupposes we actually had a true picture of what it would look like when we'd "won" but it shows how easy it can be to become...disconnected when you know that you're outta there before next fighting season.