pure logic

if country A and country B are enemies 

then it's stupid to send righteous humans from country A 

to fight righteous humans from country B 

then more unrighteous humans would survive in country A and country B 

and more unrighteous humans would reproduce 

then populations in country A and country B would devolve 

which would collapse country A and country B 

even if country C stayed out of wars 

then unrighteous humans from country A and country B would come into contact with humans from country C and they would reproduce 

then population of country C would devolve 

and country C would collapse 

smarter to send many drones with a few humans to fight wars 

better if righteous humans make their countries great