The Congressional Budget Office floated a number of cost-cutting ideas for the US federal government including reducing the number of additional Lockheed Martin F-35 Lightning II purchases, retiring the Lockheed Martin F-22 Raptor or Rockwell B-1B Lancer bomber fleets, and deferring development of the Northrop Grumman B-21 stealth bomber.

As part of a report titled “Options for reducing the deficit: 2019 to 2028”, the CBO outlined dozens of cuts in discretionary spending, within and outside of the Department of Defense, that could close the US government’s gap between revenue and expenditures. The agency’s analysis was in light of a federal deficit that is projected to rise to an average of 5.1% of GDP between 2022 and 2025 – losses which would drive the federal government’s debt to levels higher than what was incurred during World War II.

The plan to cancel additional F-35 purchases between 2019 and 2028 is estimated to save the Pentagon $13 billion, according the CBO. Instead of buying the F-35, the US Air Force would purchase 510 F-16 Fighting Falcons, and the Navy and Marine Corps would purchase 394 F/A-18 Super Hornets, through 2028. Those purchases would occur on the same schedule as that currently in place for the F-35s. The services would continue to operate the 429 F-35s that have already been purchased.

“An advantage of this option is that it would reduce the cost of replacing DoD’s older fighter aircraft while still providing new F-16s and F/A-18s with improved capabilities—including modern radar, precision weapons, and digital communications—that would be able to defeat most of the threats that the United States is likely to face in the coming years,” the CBO says. “The F-35s that have already been purchased would augment the stealthy B-2 bombers and F-22 fighters that are currently in the force, improving the services’ ability to operate against adversaries equipped with advanced air defense systems.”

There would be drawbacks as well, the CBO notes.

“A disadvantage of this option is that a force composed of a mix of stealthy and non-stealthy aircraft would be less flexible against advanced enemy air defense systems. If the United States was unable to neutralise such defenses early in a conflict, then the use of F-16s and F/A-18s might be limited, effectively reducing the number of fighters that the United States would have at its disposal,” according to the agency. “Although the Marine Corps would end up with fewer STOVL fighters capable of operating from amphibious assault ships under this option, enough F-35Bs have already been purchased to fully replace the STOVL AV-8B Harriers that perform that function today.”

However, reducing acquisitions of the F-35 would be less impactful than retiring the F-22 or B-1B, which are expensive to fly, maintain and upgrade.

“Retiring the F-22 fleet would reduce costs by about $30 billion through 2028,” says the CBO. “That amount comprises three categories of savings: operation and maintenance (about $16 billion); upgrades and modifications (about $9 billion); and military personnel (about $5 billion).”

Additionally, retiring the B-1B would reduce costs by about $18 billion through 2028, according to the CBO. Most of the savings would result from eliminating the costs for operation and maintenance of the B-1B fleet and the costs for the military personnel in the squadrons that would be inactivated.

Yet, the most impactful change in USAF procurement plans might be deferring further development of the B-21 stealth bomber, which could save about $32 billion from 2020 through 2028, according to the CBO. The B-21 is expected to enter service in the mid- to late-2020s.

One benefit of this approach would be that the B-21 programme could take advantage of forthcoming aerospace technologies not yet available, the CBO argues.

“Taking advantage of future technological developments could be particularly valuable for weapon systems that are expected to be in use for several decades,” says the agency. “Even with a 10-year delay, a new bomber would still be available before today’s bombers reached the end of their service life.”

However, the CBO notes that the USAF would be rolling the dice if it chose to delay the B-21, as by 2035, the USAF’s B-52s will be about 75 years old, its B-1Bs will be about 50 years old, and its B-2As about 40 years old. What’s more, larger numbers of stealthy bombers might be useful in operations against adversaries that employed advanced air defenses, such as China or Russia.

“Fewer bombers would be available for operations in places like the western Pacific Ocean, where long distances and limited basing options would make long-range aircraft such as the B-21 particularly useful during a conflict,” says the CBO.