SIMI VALLEY, California – After two years of military buildup, the prospect of cuts to the U.S. national security budget could have severe consequences for the Pentagon’s priorities to counter great power competition and sustain military operations around the world, Defense Secretary Jim Mattis said Dec. 1.

In his keynote speech at the sixth annual Reagan National Defense Forum at the Ronald Reagan Presidential Foundation and Institute here, Mattis emphasized that the Pentagon is “reclaiming our mantle of technological enterprise” and “signaling our determination” to boost key investment areas including missile defense, space, hypersonics and artificial intelligence. Aerial view of the Pentagon, Arlington, VA

But he warned that that progress cannot be carried forward if the budget does not reflect those priorities. “Without sustained, predictable funding, the gains we’ve made will swiftly fade and our investments will never realize their full potential,” he said. “I share a responsibility with Congress: that not just the next secretary of defense, but the secretary after next, has the military advantages necessary to deter conflict or win if we must fight.”

Mattis noted that U.S. defense spending is “near historic lows” as a share of the federal budget and the national economy, echoing a comment made earlier Saturday morning by Sen. Angus King (I-Maine) in a breakfast panel that defense spending today accounts for 3 percent of U.S. gross domestic product. By contrast, defense spending took up 52 percent of the federal budget in 1957 and 15 percent of the budget in 2017.

“Fiscal solvency and strategic solvency can co-exist,” Mattis said, adding, “Cutting defense will not close the deficit, and doing so would be a dangerous disservice to our troops and the American people they serve and protect.”

The defense secretary noted that two years ago, automatic spending cuts from the Budget Control Act resulted in the smallest U.S. military since 1940. He lauded lawmakers on Capitol Hill for passing the fiscal year 2019 National Defense Authorization Act and appropriations bills on time for the first time in a decade, saying Congress is back in “its rightful place in the driver’s seat of funding America’s national defense, rather than remaining in the spectator seat of the Budget Control Act’s mindless, automatic cuts.”

He complimented the two leaders of the House Armed Services Committee – Chairman Rep. Mac Thornberry (R-Texas) and Ranking Member Rep. Adam Smith (D-Wash.), who are all but guaranteed to switch places in the 116th Congress – on the “bipartisan nature” of their work together in the committee.

Lawmakers at the forum acknowledged that the U.S. government, from the White House to Capitol Hill to the Pentagon, needs to do more to inform the American public about the need for an increased and stable defense budget.

Undersecretary of Defense for Acquisition and Sustainment Ellen Lord said in a morning panel that the Defense Department has completed a budget request that includes $733 billion, and is currently working on a $700 billion version that lines up with President Trump’s request for a 5 percent budget cut across his cabinets.

On the same panel, Rep. Mike Gallagher (R-Wis.), a member of the House Armed Services Committee, said that the fact that the U.S. government is contemplating a $33 billion cut to a historically smaller topline “shows you how far we failed to make the case to the American public” to fund the Defense Department as needed. “To build a political coalition to continue to rebuild the modernization, we’re going to need that signal being sent from the very top of the Pentagon,” he added.