Gulf War syndrome deaths could be prevented from a combination of more research into the disorder and more treatment options. Unfortunately, there are conspiracy theories that believe Gulf War syndrome was from experiments done on troops in the field in the early 1990s. Instead, let's focus on things that can help those affected by the malady.
The US government is using quick made vaccines for anthrax and botulinum. They were also given a pill called pyridostigmine bromide to "protect" the troops against the effects of nerve agents. An alternative method of defense for the troops is in need of further development. Stop just jamming chemicals into capsules and calling the protection.
I think Gulf War Syndrome deaths could be prevented. These veterans need help. They need as much help as possible and as often as is necessary. They need medical attention, a good quality of life, rehabilitation, and people to help them get back to some semblance of normalcy in their lives.
I think most diseases can be treated, but in the case of GWS, doctors are still not even sure what is causing it. Right now all they can do is treat the symptoms without ever knowing what is causing them. I think it's an important issue that does not get enough coverage.
I don't think that Gulf War Syndrome deaths could, or can, be prevented. Like with most conditions that are psychological in nature, they can be extremely hard to diagnose correctly. Often, there are additional physical and mental problems present to further complicate the work of the clinician. Also, people are surprisingly good at hiding things that are wrong with them. If someone doesn't want to be diagnosed, it can be very hard to figure out what's wrong with them.