Given its assertion that states base their foreign policies on unsentimental assessments of their national interests, true realists would argue that there is no rational bar to enemy states sharing the same allies if doing so advances their national interests.
Ardrossan soldier Sgt Glen Gardiner, of the 2nd Battalion The Parachute Regiment, received the Military Cross for running through enemy fire to try to save the life of an Afghan National Army soldier who had been critically wounded.
Second, as an alternative to defenses, national leaders adopted a strategy of deterrence, meaning any enemy foolish enough to launch a nuclear attack would suffer devastating retaliation-in-kind.