I think the question was on the lines of "why do people think it's ok when their country does it but not ok when others do it". The answer if simple: ignorance and cognitive dissonance (hypocrisy?). Ignorance because most aren't even aware their own country engages in the exact same tactics and even far worse. And cognitive dissonance because "I must be good so my opponent must be bad" [0].

[0] https://pics.onsizzle.com/our-blessed-homeland-their-barbaro...