The accuracy and range of the modern submarine-launched cruise missile allows submarines to target about 75 percent of the Earth's land mass, which includes most of the important military targets.
Submarine-launched cruise missiles would be in the vanguard of a coordinated strike. These submarine-launched missiles would attack air defenses, early warning systems, communications, and power generation facilities to reduce the threat against follow-on aircraft. Submarine-launched missiles enhance the performance of tactical air forces by allowing tactical air assets to conduct missions other than the suppression of air defenses.
The stealth of submarines allows them to get into position without pre-alerting or provoking an adversary. The endurance of submarines allows them to remain on station for an extended period, constantly ready to conduct strikes. The agility of submarines allows them to respond quickly to new launch directives and targeting changes.