I am British citizen [born/bred] and would fight for Britain against every country on earth excluding two.
I am actually too old at 57 and at any rate I could use
conscientious objection as a means to avoid draft under British law but I guess your question is trying to draw at something deeper. So for the sake of answering your question I would accept
losing my citizenship in case I was asked to fight Pakistan [being my land of heritage] and have relatives in Pak military. I could never fight them.
It's question of blood. As regards Turkey I could never fight them although I have no Turkish heritage but my emotional investment in that great country is such I could possibly not fight them either. Thus I would be ready to surrender my citizenship.
Rest. Few like China, Iran, Afghanistan I might have some regret. Others no worries. Although if it was
India,
Bangla, Saudia, UAE [in order] I would take
particular pleasure in pulling the trigger.
@KediKesenFare @T-123456