During the Cold War, the United States relied on ICBMs because they provided accuracy that was not then achievable by submarine-launched missiles or bombers. They also provided an insurance policy in case America’s nuclear submarine force was disabled. That’s not necessary anymore. Today, the United States’ submarine and bomber forces are highly accurate, and we have enough confidence in their security that we do not need an additional insurance policy — especially one that is so expensive and open to error.

As part of the updates to America’s nuclear arsenal, the government is also planning to replace nuclear-armed submarines and bombers. If we assume that the Defense Department is critically analyzing the number of systems needed, this makes far more sense than replacing ICBMs. The submarine force alone is sufficient to deter our enemies and will be for the foreseeable future. But as technology advances, we have to recognize the possibility of new threats to submarines, especially cyberattack and detection by swarms of drones. The new submarine program should put a special emphasis on improvements to deal with these potential threats, assuring the survivability of the fleet for decades to come.

The new stealth bomber will provide a backup to submarines. This is not likely to be necessary, but the bomber force is a good insurance policy. The new bomber would be capable of carrying out either conventional or nuclear missions. But the development of new air-launched nuclear cruise missiles, which has been proposed, is unnecessary and destabilizing. We can maintain an effective bomber force without a nuclear cruise missile.