Troops who have served in Iraq and Afghanistan would prefer that you call stress related problems PTS (Post Traumatic Stress), not PTSD (Post Traumatic Stress Disorder). Actually, many troops wish everyone would revert to the older term, Combat Fatigue. What's in a word? For the troops, PTS is just another injury, and not a disorder. It's something you deal with. It wasn't always that way.
Although most troops now accept that PTSD is not a sign of mental weakness, but a very real combat hazard, many still avoid special PTSD treatment programs. However, by making PTSD treatment (which is usually just monitoring, and the use of some anti-stress medication for a while), part of regular medical care, the military had made much of the stigma disappear.
The U.S. Army has, over the years, developed a set of guidelines for how to recognize the symptoms of combat fatigue (or PTSD). With all the attention PTSD has gotten in the media of late, troops are more willing to seek treatment, or at least admit there is a problem. While extreme cases of PTSD are pretty obvious, it's the more subtle ones that army wants to catch now. These are easier to cure if caught early. But this causes problems with troops who are tagged as a "subtle case" and disagree with the diagnoses. Most soldiers still believe that, once you are tagged, you won't be left alone by all those new specialists who only want to help you.
Worse yet, the army finds itself facing several sources of PTSD. First, there was the discovery that many troops, because of exposure to roadside bombs, and battlefield explosions in general, had developed minor concussions that, like sports injuries, could turn into long term medical problems. Often these concussions were accompanied by some PTSD. The VA (U.S. Veterans Administration, which cares for injured veterans) is particularly interested in knowing about a soldier's prior exposure to roadside bombs. The troops like to point out that PTS is made worse by having too little time back home between combat tours, and this part of the problem has been addressed. But the subtle long-term effects are still only partially understood.
Another problem was that most people eventually got PTSD if they were in combat long enough. This has been confirmed by nearly a century of energetic efforts to diagnose and treat PTSD (including much recent attention to civilian victims, via accidents or criminal assault). During World War II, it was found that, on average, 200 days of combat would bring on a case of PTSD. After World War II, methods were found to delay the onset of PTSD (more breaks from combat, better living conditions in the combat zone, prompt treatment when PTSD was detected). But military historians note that successful, and often popular, commanders throughout history have paid attention to the physical well being of the troops, all in the name of "maintaining morale."
That's why combat troops in Iraq and Afghanistan often sleep in air conditioned quarters, have Internet access, lots of amenities, and a two week vacation (anywhere) in the middle of their combat tour. This has extended their useful time in combat, before PTSD (or "bad morale") sets in. No one is yet sure what the new combat days average is, and the new screening methods are an attempt to find out.
What the army does know is that a large percentage of its combat troops have over 200 days of combat. Some have three or four times that. So far, treatments (counseling and medications, for the most part) have worked. But these are not cures. A major reason for army generals talking about the army "needing a break" (from combat) is the looming loss of many combat experienced troops and leaders (especially NCOs) to PTSD. The army won't give out exact figures, partly because they don't have much in the way of exact figures. But over the next decade, the army will get a clearer picture of how well they have coped with PTSD, among troops who have, individually, seen far more combat than their predecessors in Vietnam, Korea or World War II. They may also discover that there has been some backlash to all this attention.
The army is dealing with PTSD head on, believing that what happened in Iraq, will happen again, and now is the time to get ready. Experience so far has shown that PTSD can be delayed, perhaps for a long time. When a soldier does come down with it, PTSD can often be treated, and its effects reversed. But not always. This has large ramifications for non-military medicine, for many civilians suffer from PTSD. That's because military recruits are screened for their ability to handle stress and resist PTSD. In the civilian community, there are far more people who can acquire PTSD after exposure to much less stress. What many troops wish the brass would understand is that, as recruits, they learned that stress was a major part of the job, and understood it more than the mental health mafia is willing to admit.