I presume parent is implying that war doesn't really provide any benefit to the occupants of either nation, so by expanding NATO--or otherwise encouraging 'don't start a fucking war'--we get to keep the populace out of war.

War might benefit _some_ russians, or _some_ americans, or _some_ <whatever_nation>, but I doubt that on balance 'peace' is a worse situation for most people. So, if NATO can encourage peace (even through threat of force), that's overall a benefit