How far can the Army be stretched?

According to the The Center for American Progress's National Security Team, not much further. They start out with this question:

In addition to the costs in American lives and treasure, this war now places an enormous strain on our all-volunteer Army, stretching it to the breaking point. But how bad is it overall?

You probably guessed that the team set about to answer that question. They did.

Of the Army’s 44 combat brigades today, all but the First Brigade of the Second Infantry Division, which is permanently based in South Korea, have served at least one tour [in Iraq or Afghanistan]. Of the remaining 43:
– 12 Brigades have had one tour in Iraq or Afghanistan
– 20 Brigades have had two tours in Iraq or Afghanistan
– 9 Brigades with three tours in Iraq or Afghanistan**
– 2 Brigades with four tours in Iraq or Afghanistan

The authors also note:

There is a clear cost on the troops as a result of the multiple deployments:

– An Army survey revealed that soldiers are 50 percent more likely to suffer from post-traumatic stress disorder if they serve more than one tour.
– The suicide rate among troops deployed to Iraq hit an all-time high in 2006

The report goes into a lot more depth. Its awfully sobering. Please read it for yourself.