I believe it is possible that Gulf War Syndrome could be caused strictly by war. The symptoms for Gulf War Syndrome are vast, so it could be a collection of different problems with a broad title. Given all of the veterans I'm sure there will be more information about it in the decades to come.
I do not think that Gulf War Syndrome is caused strictly due to the war in the 90s. While a lot of the cases are legitimate, some of the cases are probably fraudelant as well. I think that some people are taking advantage of the situation for financial reason and purposes.
While I think that combat or war often triggers it I think individuals the inv duals suffering from Gulf War Syndrome likely have undiagnosed psychological issues that need to be dealt with and the individuals likely would of had problems anyway in their lives even in the absence of war, something else would have triggered it.
The Gulf War Syndrome is caused by a combination of several effects not just from war itself. I think being on a foreign soil, away from family, and increase work tempo all enhance the Syndrome effect. Combine this with live combat battle and trying to survive every day takes a toll emotionally and physically on the body.
Gulf War Syndrome was not caused strictly by war. It is caused by chemicals in the air, perhaps released by the enemies onto U.S. bases at the time that might have released an agent. It is hard to actually answer, but war itself would not cause this. The agent was most likely widespread as well.