Since the end of the Cold War, the United States has undergone several bouts of unilateral disarmament in strategic arms. First, we stopped all production of tritium in 1988, a vital component in the production and refurbishment of nuclear weapons and revived it only much later (in 2005).
We conducted an unnecessary arms control agreement with Russia in 2010 - the New START Treaty - which, like virtually all previous arms control agreements with the USSR and Russia, suffered from many serious flaws. For example, it had absolutely no accompanying compliance policy. It had weaknesses in verification (which is completely distinct from compliance policy). The treaty gave Moscow unilateral advantages. It did not include a force limit on Russia's thousands of tactical nuclear weapons, an area where they far outnumber the United States. The treaty also counts certain conventional launchers against the force limit, hampering our goal of developing a Prompt Global Strike capability. These changes left Moscow a free hand to continue its nuclear modernization while we restricted the numbers of our deterrent forces without pursuing modernization.