The nuclear triad of intercontinental ballistic missiles, submarines and strategic bombers, as well as the nuclear command and control system, are at the core of U.S. defense strategy, the commander of U.S. Strategic Command told a Senate panel.

“These capabilities are foundational to our survival as a nation,” Navy Adm. Charles A. Richard told the Senate Armed Services Committee Feb. 13, appearing at a budget hearing with Air Force Gen. Terrence J. O’Shaughnessy, commander of North American Aerospace Defense Command and U.S. Northern Command.

Modernization of the triad is essential for maintaining strategic deterrence, which is foundational for everything else the Defense Department does, Richard said, adding that Russia and China are heavily investing in these systems. 

Over the decades, the return on investment in the nuclear triad has been enormous, the admiral said, noting that submarines designed to last 30 years have been in service 42 years. “What a credit to the people who designed it, built it and operated it,” he told the senators.

However, Richard said, the submarines are reaching the end of their service. “We are reaching physics and engineering limits such that you cannot extend it,” he explained. Columbia-class submarines will replace the Ohio-class submarines, he said. Funding for the first Columbia-class submarine is in the proposed 2021 defense budget.

The 400 silo-based Minuteman III intercontinental ballistic missiles were also designed with a certain lifespan, but the Air Force was able to extend it, Richard said. It will need to be replaced by the Ground Based Strategic Deterrent, another type of ICBM, which is planned for full operational capability in 2036.

In addition, Richard said, the aging B-52 bomber will remain in service for an additional 30 years, albeit with more upgrades. The other strategic bomber, the B-2, is the only long-range, penetrating stealth bomber in the world. It will eventually be replaced by the B-21, he said. The initial operating capability of the B-21 is expected to be attained by the end of this decade,  with fielding in the 2030s.

O’Shaughnessy said the nation has to invest in defensive and offensive hypersonic weapons and research because China and Russia are doing so. 

“Along with the weapons themselves, there needs to be a space-based sensor system and an over-the-horizon radar system for tracking and monitoring these and other weapons such as advanced cruise missiles,” he said. Hypersonic weapons are much faster than traditional ballistic missiles, he explained, and they’re also maneuverable.

In the past year, O’Shaughnessy said, DOD has observed a growing strategic cooperation between China and Russia — including a combined bomber patrol in July. The Chinese have also participated in multiple Russian exercises, the general said.