WASHINGTON — Who’s the top enemy of America’s new National Defense Strategy? The answer may be Congress, if lawmakers fail to act.

Defense Secretary Jim Mattis told lawmakers Thursday the strategy is “not sustainable” under budget caps due to return in 2020 and 2021, unless Congress arrives at a way to ease or eliminate them.

“If [budget caps] were to go into effect, the first cut would be $85 billion for FY20. That means the strategy is not sustainable,” Mattis told AirLand Subcommittee Chairman Tom Cotton, R-Ark.

“The strategy is designed to protect America and our interests. I could not provide you with the same strategy. I would have to rewrite it. It would be reductions in what we are able to do,” the secretary added.

Mattis, Joint Chiefs of Staff Chairman Gen. Joe Dunford and Pentagon Comproller David Norquist appeared before the Senate Armed Services Committee, where lawmakers’ questions suggested the contours of the budget battles that will follow the Pentagon-friendly two-year deal.

The Pentagon’s $686 billion budget for fiscal 2019 is the first under the new strategy, which is framed around America’s “great power conflict” with Russia and China.

Dunford’s written remarks reiterated his call for 3 percent real budget growth to preserve the nation’s military edge. He told lawmakers the strategic impact of budget caps and their enforcement mechanism ― sequestration ― hindered America’s ability to project power until recent budgets.

“If we had returned to the Budget Control Act and sequestration levels, we would not have completed the recovery we have been on,” Dunford said. “The challenges we have now took us 10 years to develop, it’s going to take us more than two to three years to recover.”

The Senate Armed Services Committee’s top Democrat, Sen. Jack Reed, of Rhode Island, suggested that beyond current “moment of stability,” Congress will be debating the FY20 budget next spring — and then, he suggested, debt will add pressure on negotiations.

Reed argued the GOP’s $1.5 trillion debt-financed tax cuts Congress passed last year will lead to ballooning deficits, which will in turn distract from thoughtful debate and responsible action on national security.

“If our nation’s fiscal strategy does not take into consideration the need for revenue, deficit-driven measures like these will likely make it exceedingly difficult to follow through with a long-term strategy with regard to any serious challenge facing us from the international arena,” Reed said.

Reed’s remarks were in the vein of the House Armed Services Committee’s top Democrat, Rep. Adam Smith, who warned Mattis earlier this month of likely deficit pressures on defense spending.

Cotton, in his questions, expressed hope that with a budget deal for 2019 in hand, Congress would have the cooperation to avoid Democratic delay tactics and pass a bill in the summer.

The goal is politically charged, as Republicans may seek to tout the bill’s passage in midterm political campaigns. Plus, Democrats have resisted passage of defense appropriations without a nondefense match, part of what’s stretched the process beyond the end of the fiscal year in recent budget cycles.

“How important is it to the Department of Defense that Congress pass a DoD appropriations bill in a timely fashion this summer as opposed to having a continuing resolution as we approach the end of this fiscal year, Sept. 30?” Cotton asked.

Mattis, in response, called it “critical, and I think that budget certainty reverberates into American industry as we try to rearm the country with the modern capability. They cannot do that … unless we give them that predictability.”

Mattis’ remarks come amid word from the Pentagon that an in-depth review of the American defense-industrial base will be publicly released in mid-May. A complementary report from the Aerospace Industries Association released this week called for robust and stable budgeting.

Joe Gould was the senior Pentagon reporter for Defense News, covering the intersection of national security policy, politics and the defense industry. He had previously served as Congress reporter.

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