From
http://en.wikipedia.org/wiki/Surviving_vet..._of_World_War_I
It appears that the latest birthdate of any of the veterans is 1901, which would entail a 17 year old age at 1918. Of course, there may have been younger veterans, but the number would be sufficiently low enough for none of them to live up to now. I think that 2010 might be the year when all WWI veterans die, unless someone pulls a Jeanne Calment.
Now, what of WWII? The number of people who fought in that war was far greater, such that I'm sure that the last veteran of that will be a child soldier by 1945. Probably in Germany, since it started recruiting mere boys to fight for their side once they got desperate. Assuming that the last substantial contingent of veterans were born in say, 1935 [not quite sure how substantial it is], perhaps we could establish with some certainty that the last one won't die before 2040; it's possible that we may see some live 100 years after the end of the war. But a lot of this is based on freak statistics => if it only turns out to be one person.
[Topics merged - ff]