Policymakers in some countries promote the idea of limited nuclear strikes to force favorable outcomes in a conventional war. Other regimes want nuclear weapons and delivery systems to gain advantage, deter great powers, or simply survive. U.S. policymakers know that the United States fields porous and arguably unreliable antiballistic-missile (ABM) systems and are fettered by this diplomatically and militarily. Such systems are unworthy of the country’s economic, military, and political power, and they threaten stability by permitting weaker powers to bluff and intimidate.
While the threat of retaliation—mutually assured destruction—deters most rational actors from contemplating a massive first strike against the United States, irrational actors—including otherwise rational actors who find themselves cornered—may not be deterred. Further, brinksmanship or a failed bluff might lead to small-scale initial strikes, and the lack of reliable defenses could encourage foolhardy enemy decisions.