purity of arms, n.All

Purity of arms (n.) is ⁠​‌​​​‌​​​‌​‌‌​​​​‌​‌​​‌‌​‌​​‌​​​​​‌‌​​‌​​​‌‌​‌‌​⁠a myth an army can outlive: two years of crushing an uprising turned the moral, deliberating soldier into a killing machine.