The United States has roughly 1,700 deployed nuclear weapons and another several thousand in reserve. Four hundred of these are on missiles in underground silos, ready to be launched in minutes. This alert status — frequently called hair-trigger alert — allows the United States to launch these missiles quickly in response to warning of an incoming attack, before attacking missiles reach their targets. 

This risky alert status, coupled with the option of ordering a launch based on warning of an incoming attack, increases the chance that a nuclear war could start due to a false alarm or other error. Maintaining hair-trigger alert options leads to unnecessarily rushed decision making. A land-based missile can travel between Russia and the United States in about 30 minutes, and a submarine-launched missile could take as little as 10 to 15 minutes. After receiving warning of an attack, military and political leaders would have only minutes to assess the credibility of this information and decide how to respond. This time pressure increases the danger of ordering a launch based on faulty information, and over the past forty years there have been numerous examples of close calls due to computer or human error.  


Hair-trigger alert is an outdated policy — the original rationale was the fear during the Cold War that either side could launch a surprise first strike that might wipe out its adversary’s ability to retaliate, which at that time largely consisted of land-based missiles and bombers. Today such an attack is exceedingly unlikely, but even if the worst were to happen, the United States now deploys more than 1,000 nuclear warheads on submarine-based missiles, hidden at sea. These sea-based missiles are not under the same pressure to be launched quickly as land-based missiles, and ensure that the United States would still be able to launch a retaliatory strike.

There is no compelling reason to maintain US missiles on hair-trigger alert, and many reasons not to. Taking land-based missiles off high alert and removing rapid-launch options from US nuclear plans would reduce the risk of nuclear use. 

“[T]he United States should remove as many weapons as possible from high-alert, hair-trigger status…Preparation for quick launch—within minutes after warning of an attack—was the rule during the era of superpower rivalry. But today, for two nations at peace, keeping so many weapons on high alert may create unacceptable risks of accidental or unauthorized launch.” 
Former U.S. president George W. Bush