The answer is NO. PERIOD.
I am writing about this because I got a call from a BBC reporter who wanted to talk to a veteran with PTSD who was being sent back to Iraq or Afghanistan.
When my husband Bob was diagnosed with "combat fatigue" about a year after he got back from Vietnam, (1966) the Army sent him the diagnosis and the information that as a result he could NEVER BE SENT TO A COMBAT ZONE AGAIN.
So what has changed?
They changed the name of the condition, but it is still the same condition.
They have new medication, but there is no medication for combat PTSD, as Jonathan Shay, MD says in his article at www.dr-bob.org/tips/ptsd.html.
There is no draft, but they need more soldiers than they have.
The job of psychiatrists today is to give pills, not find out what is torturing their patients.
The job of military patients, who are in because they want a military career, is to shut up and take the pills so they don't lose their careers.
It is the political situation that has changed.
Politics, as usual, sends people back into hell.
What is the evidence for it being safe? As far as I know there is none. Israeli studies of their multi-war vets showed that those who had PTSD got it faster and worse in the next war.
This is one of those cases where what should be (It ought to work, sending them back on meds) trumps actual experience. We see WWII, Korean, and Vietnam vets with long term effects from war, but this time it's different. We have medications! Well most of those veterans were SELF-MEDICATING all along, and it didn't work. But we have better meds. Oh, yeah? Where are the randomized double-blind trials to prove it. There are none.
It is like the earlier denial and delusion period of American psychiatry-1968 to 1980-when on no scientific evidence, any diagnosis which derived from traumatic events was dropped because people, normal people, "shouldn't" be affected by horrific experiences. Guys with couches decided that. Guys with pill bottles are deciding this.
Recovering from traumatic events takes time, just like recovering from a physical wound. This is a stress injury, not a chemical problem. Even if the chemistry is changed by the experience that should be a hint to everyone that war is not good for people. Our bodies are designed to react to stress and to AVOID it. Most PTSD symptoms start out as brain-and-body based, built-in survival mechanisms, which keep you alive and get you out of there! Modern warfare is designed to provide stress after stress after stress. Pills will numb your edge and, in my humble opinion, get you in worse shape. They may help when you get back as you work on recovery, but they are not recovery.
What works for emotional numbing and avoidance? Feeling the pain of your dead buddies, working through the stages of grief. There is no pill for that. It takes time.
What works for hyper-arousal? Somatic therapies, meditation, learning people-skills like "We can agree to disagree," etc. Learning to avoid triggers. Learning to identify triggers. Learning how to bring yourself back to the present when you are triggered.
What works for re-experiencing? Going through the story of what happened and turning it from fragments of smell, sound, vision, emotion, into a coherent narrative which moves it from your reptile brain up into your narrative memory in your fore-brain.
There are many methods which work to do these things. Probably the fastest is TIR (Traumatic Incident Reduction, www.tir.org). Most of them take TIME and time is what the current situation does not allow for, nor military culture, nor the culture of current psychiatric practice which is heavily influenced by the major drug companies.
It is not ethical. First do no harm. Sending them back with PTSD harms our soldiers.