Though red poppies are worn with general intention to commemorate the sacrifices and service of war veterans, they specifically relate to the harrowing conflicts, solace, and eventual armistice of World War I. Though World War II succeeded it as directly consequential, we can discuss that "good war" as the fight against the fascism that was originally favoured to be appeasement by aristocratic powers. I could elaborate that WWI embodied nothing but mass suffering, genocide and mass, expandable deployment of young men (my great-grandfather Thomas Richardson being one of them) in the name of nothing but imperialistic colonialism by pitiful and jingoistic political agendas (which it was), compared to the home front-style resistance movement pioneered by Michael Foot's Guilty Men and the speeches of Winston Churchill. But this would be intellectually and ethically dishonest. Though taking the side of Soviet totalitarianism was justifiable in the longterm, atrocity and abomination is inherent to all mass warfare. We have no need to mention the Holocaust. But we should put the bombing of Dresden or the U.S. nuclear obliterations of Japan on par with it.
When the commemorative red poppies were first introduced in 1926, socialist pacifists and war widows proposed that "No More War" be painted in their middles. When these efforts failed, they created their own white poppies, bearing "Peace" (which you can buy here). Of course, these are only matters of interpretative symbology. I choose to wear both the red and white poppy on the same lapel, in both warning and tribute to the crimes and liberations of armed struggles.