A nuclear deterrent is a military strategy that uses the threat of nuclear weapons to prevent an enemy from taking aggressive actions. The idea is that if a country possesses nuclear weapons, potential adversaries will be discouraged from attacking, knowing that the consequences would be catastrophic. Countries like the United States and Russia maintain nuclear arsenals as a form of deterrence. This strategy aims to ensure national security by creating a balance of power, where the risk of mutual destruction keeps conflicts from escalating into full-scale wars.