In war all parties engage in actions which could be described as "war crimes" (depending on your personal definition I guess). However, only the losers get tried. To paraphrase Robert McNamera, if the U.S. had lost the Second War War those responsible for the firebombings of Japan would considered war criminals...

For my answer: No, they should not be tried. It would be absurd and who has the political authority to prosecute them? Surely not the U.N. Any kind of "trial" would just be a useless exercise of political showmanship.