America’s nuclear arsenal is getting billions of dollars more expensive with each passing year, the Obama administration said in a recent report to Congress obtained by CQ.

The report shows how nuclear weapons costs are beginning to crest as the Pentagon and the Energy Department move into a $1 trillion modernization effort over the next three decades. It is the biggest looming issue in the defense budget.

From fiscal 2017 to 2026, it will cost $341.78 billion, including inflation, to buy and sustain new nuclear submarines, aircraft, missiles, bombs, warheads and associated computers, according to the report.

Last year, the administration told Congress that the cost from fiscal 2016 to 2025 of the nuclear arms program was $319.8 billion — or $22 billion less.

The rise in budgets is due partly to some new or expanded plans, but mostly it is a function of programs moving into more expensive phases of late development or early production.

The unclassified document, a summary of a classified report, was submitted to Congress late last year. The document’s total cost implications for the nuclear budget have not been previously publicized.

The cost of the nuclear arsenal could balloon further still if President-elect Donald Trump makes good on recent promises.

“The United States must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes,” Trump tweeted Dec. 22.

“Let it be an arms race,” he told MSNBC the next day. “We will outmatch them at every pass and outlast them all.”

The high and rising cost of maintaining, if not expanding, U.S. nuclear weaponry will be a major debate in Congress in the next several years. The two parties take contrasting approaches to the issue.

Sen. Dianne Feinstein of California, the top Democrat on the Energy and Water Appropriations Subcommittee, which funds Energy Department nuclear programs, told CQ that the swelling cost of nuclear arms is “devastating for everything else” in the budget.

“As this goes up, it just smashes against the other things that should be done,” she said. “It’s a real problem.”

Republicans generally have a different perspective.

“If we’re going to be the No. 1 power in the world militarily, we’re going to have to pay for it,” said Alabama Republican Sen. Richard C. Shelby, another senior appropriator, in a brief interview. “We’ve got to modernize our nuclear arsenal.”

Swelling cost projections

Several programs account for most of the higher 10-year nuclear cost estimate since last year.

A dozen new nuclear-armed subs, known as the Columbia class, will cost $8.4 billion more from fiscal 2017 through 2026 than was projected last year for the fiscal 2016 through 2025 timeframe, the report said. A planned intercontinental missile, the Ground Based Strategic Deterrent, would cost $4.8 billion more. The Long Range Standoff Cruise Missile would cost $900 million more. Nuclear command and control systems will cost $3 billion more. The Energy Department’s weapons stockpile and supporting infrastructure will cost $4.3 billion more.

Some new programs are included, such as a $2.7 billion initiative to replace aging Huey helicopters that ferry security forces charged with protecting ground-based missile fields that are scattered across hundreds of miles in the northern Great Plains.

The report may understate the full cost of nuclear modernization for several reasons, apart from the fact that it only addresses the next ten years’ costs. It does not include a likely new submarine-launched missile program that has yet to get going. Secondly, it is not clear if the most recent estimate includes a larger total acquisition cost projection for the Ground Based Strategic Deterrent — $85 billion today, up from $62 billion last year. And the report does not reflect the likelihood of historical rates of cost growth.

Most importantly, the projected increases may only foreshadow larger price hikes to come, because expenditures on nuclear modernization will not peak until after the report’s 10-year window.

“This snapshot captures the beginning of the major planned ramp up in spending on nuclear forces, but even larger bills are still to come,” said Kingston Reif, an expert on nuclear budgets with the Arms Control Association. “The current approach is unnecessary and runs a high risk of forcing damaging cuts to higher priority national security programs if pursued to completion.”

On the other hand, the costs may be overstated in at least one respect. Some of the weapons included in the tally are used partly, if not mostly, for non-nuclear missions. So it may not be fair and accurate to attribute, for example, the full cost of a bomber that performs mostly conventional missions to the nuclear account.

The Trump administration and the new Congress have options for cutting costs on nuclear modernization, the Congressional Budget Office reported last month. The government could save tens of billions of dollars over the next 10 years alone by reducing the number of Columbia class subs, ground-based missiles and deployed warheads. Other options for savings include delaying the bomber program and cancelling the proposed new nuclear cruise missile, CBO said.

B-21 budget in dispute

The new cost projection for the next decade of atomic weapons spending is rising despite a $3.2 billion drop in the estimate for development and early production of new B-21 Raider bomber jets over the first decade of that program’s life.

But Senate Armed Services Chairman John McCain, R-Ariz., among others, has questioned the validity of the lower B-21 estimate, which is based on a bid by prime contractor Northrop Grumman Corp. that came in far below the Pentagon’s own estimates — unrealistically low, some say.

Conferees writing the final fiscal 2017 defense authorization bill diluted a Senate provision that would have held the B-21 program to the same consequences for cost growth that the vast majority of other major programs must meet. The Pentagon considers the B-21 a special acquisition and exempts it from a termination review if costs exceed certain thresholds.

McCain, who voted for the final bill, told CQ Roll Call last month that the conferees’ changes were “absolutely unconscionable.”

The Air Force has declined to disclose the total acquisition cost for the B-21 bomber or the total amount of Northrop Grumman’s contract to develop and start building the first 21 planes — figures the Air Force and other services routinely reveal, even for highly secretive programs.

The Air Force’s unusual reticence to disclose the information has been criticized by McCain and some other lawmakers, as well as by taxpayer watchdog groups and arms control advocates.