Yes.
I spent a term at Leningrad Uni back in '82 and recall seeing the veterans marching on Victory Day. Two of my university lecturers in Leningrad* were decorated veterans - one was a lovely woman who had been a nurse on the front line. Another lecturer had been a child during the war and recalled helping to clear bodies in order to stop an outbreak of plague following the siege.
The poppy is in memory of those who fell whilst fighting for their country - whether or not you approve of the cause that they fought for, it's in memory of them.
I wear mine in memory of all, but particularly in memory of my great-grandfather and FIL's brother, both of whom fell in the Great War. The former died fighting to save his country against an invading army. In my G-G's country, a different flower is worn, but they also honour the memory of British women doctors and nurses who came to their aid at that time, so I'm certain that G-G would approve of the poppy.
I also wear my poppy in memory of those who suffered lifelong trauma and injury, including several of my family members.
*Yes, I know that it's once again St Petersburg. [Adding this because I've been corrected by young Russians on more than one occasion. It was called Leningrad when I was there.
Insert the old joke about the elderly man who was born in Peterburg, brought up in Petrograd and then Leningrad but hoped to die in Peterburg.]