Several nuclear states, including China, India, and most recently North Korea, have pledged to never use nuclear weapons unless they are first attacked with nuclear weapons: a "no-first-use" or "no-first-strike" policy. The United States should adopt such a policy to (1) renew its commitment to international nuclear non-proliferation, and (2) strengthen the international norm that nuclear weapons are taboo, which has arguably been the most effective preventive of nuclear war.
Far from emboldening our enemies, a no-first-use policy would signal to other nuclear powers that they need not fear a nuclear first strike by the US, thus reducing their incentive to stockpile nuclear weapons, and ensuring the safety of Americans from the threat of nuclear war.