In a rare move, top Republican defense leaders in Congress issued a pointed warning to former President Donald Trump this week over reported plans to significantly alter U.S. military leadership and force posture abroad.

The joint statement from House Armed Services Committee Chairman Mike Rogers (R-Ala.) and Senate Armed Services Committee Chairman Roger Wicker (R-Miss.) follows a report from NBC News that Trump is considering pulling back U.S. military leadership in NATO and scaling back American forces in Japan—two longstanding pillars of American defense policy.

The GOP leaders expressed deep concern over any such changes being made unilaterally and without proper coordination.

“We will not accept significant changes to our warfighting structure that are made without a rigorous interagency process, coordination with combatant commanders and the Joint Staff, and collaboration with Congress,” Rogers and Wicker wrote.

According to the NBC report, Trump is contemplating abandoning the role of NATO’s Supreme Allied Commander Europe—an influential military post historically held by a U.S. general—and canceling a planned expansion of American forces in Japan.

Neither the White House nor the Department of War has officially confirmed any such decisions.

These rumored moves would mark a sharp departure from decades of American defense strategy and leadership.

The role of NATO Supreme Allied Commander Europe, currently held by Army Gen. Christopher Cavoli, has always been filled by an American officer since the position’s inception during the Cold War.

It was first occupied by Gen. Dwight D. Eisenhower and remains a cornerstone of U.S. military influence in Europe.

Wicker and Rogers acknowledged they support Trump’s broader efforts to press allies for greater defense spending but cautioned against sacrificing U.S. global leadership in the process.

“We broadly support President Trump’s efforts to ensure our allies and partners increase their contributions to strengthen our alliance structure,” they said, “but continued American leadership is critical to maintaining peace and stability.”

They added that pulling back from leadership roles in NATO or the Pacific would “risk undermining American deterrence around the globe and detracting from our negotiating positions with America’s adversaries.”

Trump has frequently criticized NATO during his political career, claiming that European allies rely too heavily on U.S. defense spending.

However, the idea of stepping back from NATO leadership or reducing presence in the Indo-Pacific has raised alarm among lawmakers, even within his own party.

The unusual public rebuke also comes on the heels of controversial personnel changes within the Pentagon. Last month, Defense Secretary Pete Hegseth, a Trump ally, removed several top military officials including Joint Chiefs Chairman Gen. CQ Brown, Chief of Naval Operations Adm. Lisa Franchetti, and Air Force Vice Chief of Staff Gen. Jim Slife.

While Democratic lawmakers condemned the moves, most Republicans remained quiet—making the new statement from Rogers and Wicker all the more notable.

Both Armed Services Committees are expected to hold posture hearings in the coming months to evaluate the military’s strategic plans in Europe, the Pacific, and other key regions.

Whether Trump’s rumored shake-ups materialize remains to be seen, but GOP leaders have now drawn a firm line on how those decisions must be made.