I suppose you could possibly argue for the Eastern Empire? Maybe? But then that's still built upon the core of the original polytheistic structure, and I don't think it's a strong argument that Christianity played into it.
If anything Christianity seems to cause a problem for organized military - after Rome we don't see an organized, professional military for another thousand years. People may think of "the crusades", but let's be honest, the majority of that was really more a rag-tag rabble causing trouble, rather than any sort of organized and united fighting force.
If anything Christianity seems to cause a problem for organized military - after Rome we don't see an organized, professional military for another thousand years. People may think of "the crusades", but let's be honest, the majority of that was really more a rag-tag rabble causing trouble, rather than any sort of organized and united fighting force.