If the guy you are researching is a relative of yours, I suggest you write a letter to your country gouvernment's Veteran Department. I did it myself for two of my ancestors (one in WWI (tuned up he never was enlisted/drafted) and an other in WWII).
However, the process can take some time. I sent the letter about a month ago and I received an answer about a week after. It was telling me the result for the WWI search and that the WWII search would be longer, as they are giving priority to the veterans/families who are requesting stuff like lost medals or pensions. They said I should receive an answer in about 8 months.
Of course, if you do so, be very accurate on the info you give... As there can be more than one veteran named "John Doe".