Map Shows US Regional Unified Combatant Commands. Left to right: This Newsweek map shows U.S. military combatant commands with regional focuses, including Northern Command, Southern Command, European Command, Africa Command, Central Command, and Indo-Pacific Command. Newsweek
Senior Republicans have said they are "very concerned" about reported Pentagon discussions on widespread changes to the U.S. military structure and footprint abroad, as extensive government cuts start to reach the Department of Defense.
Why It Matters
The U.S. has the West's most powerful military, and a global footprint to both support its allies and to deter its adversaries in different regions.
But the Trump administration has turned away from Europe, where the U.S. military has tens of thousands of personnel stationed, and looked toward how it will contend with the challenge posed by an ascendant China.
There are also growing concerns among current and former military figures and experts about how senior White House officials have thawed relations with Russia and purged several of the highest-ranking U.S. military figures, including the former chairman of the Joint Chiefs of Staff, Air Force General Charles Q. Brown Jr.
Defense Secretary Pete Hegseth said last month that the Pentagon would be leaning heavily on tech billionaire-turned-presidential aide Elon Musk and his Department of Government Efficiency (DOGE) to "find fraud, waste and abuse in the largest discretionary budget in the federal government."
What To Know
Republican Alabama Representative Mike Rogers, who heads the House Armed Services Committee, and Republican Senator Roger Wicker, the chairman of the Senate Armed Services Committee, said in a joint statement that they were "very concerned about reports that claim DoD is considering unilateral changes on major strategic issues, including significant reductions to U.S. forces stationed abroad, absent coordination with the White House and Congress."
Newsweek has reached out to the Pentagon for comment via email.
NBC News reported on Tuesday, citing two defense officials and a Pentagon document seen by the outlet, that the Trump administration is considering giving up America's hold on the role of NATO's Supreme Allied Commander Europe, colloquially known as SACEUR.
Of the U.S. military's 11 combatant commands, five could be blended under a new plan, the two defense officials also told the outlet. U.S. European Command and U.S. Africa Command could be merged into one command based in Germany, as could the Florida-headquartered Southern Command with the Northern Command, according to the report.
CNN also reported that the Northern and Southern Commands could morph into one dubbed AMERICOM, citing a document seen by the network. Another option on the table was to halt plans to build up U.S. Forces Japan, according to the CNN report.
This could generate "political risk" for the U.S. in the country and restrain Washington in the Pacific, the network reported, citing the briefing document. The previous administration under President Joe Biden moved to make U.S. Forces Japan a joint force headquarters accountable to the commander of INDOPACOM, in what then-Defense Secretary Lloyd Austin called a "historic decision."
"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," the Republican lawmakers said in their joint statement.
"Such moves risk undermining American deterrence around the globe and detracting from our negotiating positions with America's adversaries."
What Are Combatant Commands?
The Defense Department's 11 unified combatant commands each comprise units from multiple U.S. military service branches. They are assigned areas of responsibility based on geography or function.
The combatant commands are the main mechanism through which the U.S. conducts global military operations, including peacetime training exercises and wartime combat missions. The requirements of each command—often based on the capabilities and intentions of specific adversaries—ultimately inform the Pentagon's equipment and manpower needs.
The U.S.'s seven regional combatant commands are:
U.S. Northern Command (NORTHCOM), headquartered at Peterson Space Force Base in Colorado and responsible for the continental United States, Canada and Mexico.
U.S. Southern Command (SOUTHCOM), headquartered at Peterson Space Force Base in Colorado and responsible for Central America, South America and the Caribbean.
U.S. European Command (EUCOM), headquartered at Patch Barracks in Stuttgart, Germany, and responsible for Europe, as well as parts of Central Asia and the Arctic and Atlantic oceans.
U.S. Africa Command (AFRICOM), headquartered at Kelley Barracks in Stuttgart, Germany, and responsible for all of Africa except Egypt.
U.S. Central Command (CENTCOM), headquartered at MacDill Air Force Base in Florida and responsible for the Middle East, including Egypt, as well as parts of Central Asia and parts of the Indian Ocean.
U.S. Indo-Pacific Command (INDOPACOM), headquartered at Camp H.M. Smith in Hawaii and responsible for the East, Southeast and South Asia, the Pacific Ocean and parts of the Indian Ocean.
U.S. Space Command (SPACECOM), headquartered at Peterson Space Force Base in Colorado and responsible for combined U.S. operations in the space domain.
The U.S.'s four functional combatant commands are:
U.S. Cyber Command (CYBERCOM), headquartered at Fort Meade in Maryland and responsible for directing U.S. cyberspace forces.
U.S. Special Operations Command (SOCOM), headquartered at MacDill Air Force Base in Florida and responsible for directing U.S. special operation forces.
U.S. Strategic Command (STRATCOM), headquartered at Offutt Air Force Base in Nebraska and responsible for directing U.S. strategic forces.
U.S. Transportation Command (TRANSCOM), headquartered at Scott Air Force Base in Illinois and responsible for land, air and sea transportation for the U.S. Defense Department.
Chain of Command
How the U.S. organizes and controls its forces is largely influenced by "inherent tension between improving the effectiveness of U.S. forces, on the one hand, and preserving civilian control of the military, on the other," international security specialist Kathleen McInnis wrote in a report last year for the Congressional Research Service.
"Perceived shortcomings in the U.S. chain of command led to demonstrable failures during several incidents in the late 1970s and early 1980s," said McInnis, who is now a senior fellow at the Center for Strategic and International Studies, a Washington think tank. "The military services, in the view of many observers, failed to effectively plan or conduct operations jointly due to confusion over whether the military services or unified combatant commanders were ultimately in charge of operations."
In military operations today, leaders of U.S. combatant commands—all Senate-confirmed four-star generals or admirals—are third in the chain of command, after the president and the defense secretary, and liaise with the chairman of the Joint Chiefs of Staff.
In certain regions, combatant commands also oversee subordinate commands. INDOPACOM, for instance, also directs the U.S. Forces Korea and the U.S. Forces Japan—more than 80,000 active service members forward-deployed to allied bases near Russia, North Korea and China.
What People Are Saying
Rogers and Wicker said in a joint statement that "such moves risk undermining American deterrence around the globe and detracting from our negotiating positions with America's adversaries."
Related Articles
Which US Weapons Sales Could Be at Risk Amid Trump Backlash in Europe?
Pentagon Received Faulty Armor Plates from Russia-Owned US Plant: Report
Russian Was Captain of Ship That Crashed Into U.S. Military Supply Vessel
How NATO Without US Stacks Up Against Russia
2025 NEWSWEEK DIGITAL LLC.
This story was originally published March 21, 2025 at 4:00 AM.