dark arts

I'm going to assume 

that most personnel in special operations units of country A 

knows dark arts 

and I think it would be practical 

if atleast a few personnel in special operations units of country B 

knows dark arts 

maybe it's time to learn dark arts 

if official personnel of special operations units 

wants to use uniforms, gear and weapons 

in official operations 

then that's fine 

and if covert operators of special operations units 

wants to use civilian clothes, civilian gear and civilian weapons 

in covert operations 

then that's fine 

but if deniable operators of special operations units 

wants to achieve results 

in deniable operations 

then they need to learn dark arts