US and Russian forces have Launch-On-Warning (LOW) capability
Through the possession of launch-ready nuclear-armed missiles, Early Warning Systems and nuclear command and control networks, the US and Russia the capability to Launch-On-Warning (LOW) warning of attack. That is, the combination of these systems gives them the capacity to detect an enemy nuclear attack and order a retaliatory launch of nuclear-armed missiles (based upon a warning of this attack) before the arrival of the perceived attack is confirmed by nuclear detonations. The US and Russia are the only two nations believed to have the capacity to carry out Launch-On-Warning.
When Early Warning Systems warn of an impending nuclear attack, then decisions on how to respond to the perceived attack have to be made very quickly because the flight times of the missiles are very short. 30 minutes or less are required for a nuclear-armed land-based Intercontinental Ballistic Missile (ICBM) to travel between the U.S. and Russia and vice versa; 15 minutes or less for a Submarine Launched Ballistic Missile (SLBM) to reach its target. New Russian hypersonic weapons will likely reduce these time frames.
Thus, once the attack is detected, evaluated and passed up the chain of command, the U.S. and Russian president would have at most 12 minutes (only 2 or 3 minutes for an attack launched by a nuclear sub) to make the decision to launch a retaliatory nuclear strike before the arrival of the perceived attack. If the perceived warning turns out to be false but a retaliatory nuclear strike has already been launched, then accidental nuclear war will have occurred.
Despite the apparent dangers of LOW, the US and Russia for decades strove to minimize their launch times, and this situation seems to continue even to this day. Because both nations fear a nuclear attack would destroy their command and control systems and silo-based forces, and because they know that their military plans will list each other’s nuclear forces as primary targets in the event of war, this creates in essence a de facto Launch-on-Warning policy for both sides.
US officials have, in the past, acknowledged the US LOW capability, but have never conceded that LOW is a fundamental part of US operational nuclear policy. Retired military officers (including the late Dr. Bruce Blair, a former Minuteman launch officer) have told us that this capability was long ago converted into policy and standard operating procedure, and that such policy still remains in place today.
Russia also will not admit that LOW is central to its operational planning, although a former high-ranking officer who served in the Soviet General Staff has written that LOW still is a standard operating procedure in Russia’s Strategic Rocket Force.
Elimination of launch-ready nuclear weapon systems would, by definition, eliminate the ability of the U.S. and Russia to Launch-On-Warning, and thus make impossible the launch of a retaliatory nuclear strike based upon a false warning.