Hi, thank you so much for your service, and I am so sorry to hear you have been dealing with RA for over 10 years now. I have also heard the similarities between "Gulf War Syndrome" and RA, but of course, I cannot say if one caused the other. I think it would be interesting to ask your doctor (depending on their age), if they actually experienced patients during that time that served in the Gulf War and were diagnosed with RA. Here is a link of a study that was done in 1998.
https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/191436
Grady EP, Carpenter MT, Koenig CD, Older SA, Battafarano DF. Rheumatic Findings in Gulf War Veterans. Arch Intern Med. 1998;158(4):367–371. doi:10.1001/archinte.158.4.367