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.

FORBES: Nuclear Weapons: How Few Is Too Few?

All of this is not to say that certain concepts of Cold War era deterrence strategy are not still applicable.

CENTERFORSECURITYPOLICY: Peace through strength in a globalized world

The only truly successful way to address the problem in the long term is through a strategy that focuses on deterrence, security, the rule of law and development.

UN: Secretary-General