I read recently that the US Army is thinking of shortening it’s tour of duty policy in Iraq to less than one year.
This got me thinking about the way they rotate troops. During the Vietnam War the Australian Army rotated units in their entirety in and out, whereas the US Army kept units in country and rotated troops in and out. This second method is apparently cheaper and administratively easier to keep units up to strength, but has serious knock effects to unit cohesion and morale.
The US is using the unit rotation method in Iraq as much as they can.
Frankly, I don’t know what method the inactive force types(National Guard) the US used in Vietnam. There were some units that were activited then but the numbers were relatively smaller.
The Vietnam era draft permitted or perhaps required the individual soldier method.
The total military term requirement for the draft was generally 18 months, the Guard six years.
The Cold War required that we retain a large standing army, and a forward-deployed one at that, in nominal peacetime (something we never had pre-WW2). This army had the peculiarity of permanent forward deployment of units that HAD to stay put in their respective fronts – no pulling units from Germany to cover Iraq, say. So the units stayed put and the people rotated through them. When of the draftee’s 2 years only 1 year would be the in-country combat tour, you pretty much had to do that.
Actually, it depended on how you were assigned. In my case, I was assigned to the Naval Support Activity near Danang. As a support facility, the rotations were individual. Seabees in a deployed battalion, OTOH, rotated as a unit.
In my case, I experienced both - immediately prior to Gulf War One I was assigned to 3/75 Ranger Battalion in Ft. Benning. As Desert Shield prepared to turn to Desert Storm, I was transferred to the 3/325 ABCT (Airborne Battalion Combat Team) in Vicenza, Italy, and rotated in prior to the unit’s deployment. I was transferred as they needed additional LRRP soldiers for the ABCT’s recon squads.
When I arrived in Vicenza, the unit was just transitioning from being the 4/325, out of Ft. Bragg, part of the 82nd Airborne. What they did was swap out the unit, but not the personnel. So I guess what happened in practice was that the personnel stayed, but they administratively just swapped the personnel and TOE. I don’t actually know if they swapped the command structure as well - the officers might have rotated back, but I’m pretty sure at least the company level officers and below stayed. WAG, though.
Later the unit swapped out of regiment, too. Last I heard it was the 1/507 ABCT there now.