Defense Primer: U.S. Northern Command (USNORTHCOM)
U.S. Northern Command (USNORTHCOM, commonly referred to as NORTHCOM) is the U.S. Department of Defense (DOD) unified combatant command (CCMD) responsible for the defense of North America. The term unified refers to "a military command which has broad, continuing missions and which is composed of forces from two or more military departments," according to 10 U.S.C. §161 The commander of NORTHCOM also commands the North American Aerospace Defense Command (NORAD), a binational command shared with Canada that is responsible for aerospace warning, aerospace control, and maritime warning for North America.
Background
Following the terrorist attacks of September 11, 2001, President George W. Bush directed changes to the Unified Command Plan, a classified executive branch document that outlines CCMD missions and responsibilities, and created NORTHCOM. DOD gave NORTHCOM responsibility for providing command and control of homeland defense efforts and for coordinating defense support of civil authorities (DSCA). The command, established on October 1, 2002, initially focused on threats from international terrorism. The global strategic environment evolved over the years, and the command assessed in 2025 that vulnerability to adversary conventional, non-kinetic, and strategic military threats also poses risks to the U.S. homeland. According to NORTHCOM, the command's homeland defense operations range from "arctic security" and "border security" to countering "aerospace warning and control" and "missile defense."
Mission and Organization
NORTHCOM states that its mission is to "defend our homeland—deter, detect, deny, and defeat threats to the United States, conduct security cooperation activities with allies and partners, and support civil authorities." A geographic CCMD, the NORTHCOM area of responsibility (AOR) spans the continental United States, Alaska, Canada, Mexico, and surrounding waters "out to approximately 500 nautical miles," including the Gulf of America (also known as the Gulf of Mexico), the Straits of Florida, and areas of the Caribbean region (see Figure 1). On June 17, 2025, DOD announced the transfer of Greenland from U.S. European Command (EUCOM) to NORTHCOM's AOR.
Led by a four-star general or admiral, NORTHCOM is headquartered at Peterson Space Force Base, Colorado. NORTHCOM's current commander is U.S. Air Force General Gregory Guillot.
Components
NORTHCOM states that it has "few permanently assigned forces" and instead "is assigned forces whenever necessary to execute its missions, as ordered by the president or the secretary of defense." The command is organized into four service components commands: U.S. Army North, U.S. Naval Forces Northern Command, Marine Corps Forces Northern Command, and Air Forces North/First Air Force; two subordinate unified commands: Alaska Command and Special Operations Command North; and five joint task forces (JTFs): JTF-North, JTF-Civil Support, JTF-National Capital Region, JTF-Southern Border, and Joint Intelligence Task Force-Southern Border. In February and March 2025, respectively, NORTHCOM established Joint Intelligence Task Force-Southern Border and JTF-Southern Border to tactically synchronize DOD activities and military forces supporting operations at the U.S. southern border.
Approximately 1,700 military and civilian personnel are directly assigned to NORTHCOM headquarters, with additional joint force personnel assigned across the command's components.
|
Source: Created by CRS. Data from DOD. Date of map: June 18, 2025. |
North American Aerospace Defense Command
In 1958, the common defense of North America and the establishment of NORAD was formalized by an agreement between the U.S. and Canadian governments. In 2006, the agreement was renewed, adding a maritime warning mission to the command's responsibilities. The commander of NORTHCOM is dual-hatted, also serving as the commander of NORAD. These personnel are led by a U.S. Commander and a Canadian Deputy Commander who are appointed by, and report to, both the President of the United States and the Canadian Prime Minister. NORTHCOM and NORAD are separate commands integrated through their shared command structure, a unified command center, and a common mission of defending North America.
Budget
DOD budget documents do not fully enumerate funding for CCMDs. Forces and operations assigned to CCMDs typically are funded by individual military services, with CCMD funding largely limited to operations and maintenance accounts for headquarters and mission support activities. The military departments serve as combatant command support agents (CCSAs), assisting assigned CCMDs with logistical support via their annual budget requests. The Department of the Air Force (DAF) serves as the CCSA for NORTHCOM. For FY2025, the DAF requested $212.3 million for NORTHCOM and NORAD headquarters operations. For FY2025, the command provided Congress a $34.7 million unfunded priorities list. The list focused on upgrading information technology systems supporting NORAD and NORTHCOM strategic efforts toward "digital transformation," "Homeland Defense," communications upgrades for subordinate air surveillance units, and the Arctic Security Initiative (see §1090(b) of P.L. 117-81).
NORTHCOM Strategic Concerns
In his February 2025 posture statement to the Senate Armed Services Committee, General Guillot highlighted areas of strategic concern to NORAD and NORTHCOM:
- The increased likelihood of a direct conflict between the United States and the People's Republic of China (PRC), Russia, North Korea, or Iran, and the increased strategic cooperation among these four countries
- Adversarial development of capabilities and rehearsal of plans that threaten North America, including threats such as "small uncrewed aircraft systems (sUAS) operating over sensitive DoD installations and other Defense Critical Infrastructure," and increased cyber operations targeting defense and civil infrastructure
- The threat of a foreign terrorist attack in North America by non-state actors
- Transnational criminal organizations based in Mexico that threaten U.S. sovereignty "through the production and trafficking of fentanyl and other illicit drugs and the facilitation of unlawful mass migration"
Potential Issues for Congress
CCMD Missions and Responsibilities
Under 10 U.S.C. §161, Congress has delegated to DOD the authority to alter, adjust, create, or disestablish CCMD structures, missions, and geographic AORs. Congress may consider whether or not to retain the authority to direct or prohibit such realignments. Congress previously has legislated provisions that have altered, adjusted, created, or prohibited the adjustment of CCMD structures.
In February 2025, Trump Administration officials reportedly indicated they were examining the restructuring of some CCMDs, including a potential merger of NORTHCOM and U.S. Southern Command (SOUTHCOM). Such a consolidation could create a command responsible for aerospace and maritime activities for all of North, Central, and South America.
On June 17, 2025, DOD announced that President Trump "ordered a change to the Unified Command Plan" that shifted Greenland from EUCOM to NORTHCOM's AOR. Greenland, a self-governing part of the Kingdom of Denmark, hosts Pituffik Space Base, where some DOD space surveillance and missile early warning operations are conducted. Some observers have suggested that moving Greenland to NORTHCOM's AOR could, among other goals, "help the U.S. broaden its Golden Dome missile shield" and monitor security conditions in the Arctic. Others have expressed concern that such a move may increase tensions with Denmark and other European allies.
Congress could consider the feasibility, risks, benefits, and costs of such consolidations, alternative structures, or changes in responsibility and how such changes could affect U.S. national security interests. Congress also could consider directing a report analyzing such considerations and integrate the findings and recommendations into future CCMD hearings or defense-related legislation.
Counter Unmanned Aerial Systems
In February 2025, some Members sought information from DOD regarding DOD and NORTHCOM's Counter Unmanned Aerial Systems (C-UAS) homeland defense strategy and capabilities. Ukraine's June 1, 2025, drone strikes in Russia furthered debate on the issue, with some Members expressing concern regarding vulnerabilities to such a threat in the U.S. homeland. Congress may consider whether to provide DOD with additional authorities to conduct C-UAS operations in the United States or whether to extend DOD's existing authorities beyond December 31, 2026 (when DOD's existing authorities are set to expire). Congress also may consider to whether or not C-UAS should be integrated within the proposed Golden Dome defense framework.
Military Operations on the Southern Border
Through oversight and funding authorities, Congress may influence the role NORTHCOM plays in supporting the U.S. Department of Homeland Security and other agencies working to secure the U.S.-Mexico border. On January 20, 2025, President Trump issued a proclamation declaring a national emergency at the U.S. southern border, citing cartel activity, drug trafficking, and unauthorized migration. Invoking the National Emergencies Act (NEA; 50 U.S.C. §1631), President Trump authorized the Secretary of Defense to deploy troops and additional resources (e.g., unmanned aerial systems, physical barriers) to the border. A mix of Title 10 forces and state-activated National Guard personnel have deployed to the southern border. Congress could assess the extent to which conditions at the southern border meet NEA criteria and whether such deployments are still required.
Readiness
Some Members of Congress have expressed concerns about the extent to which DSCA efforts on the southern border might affect readiness by diverting military personnel from training for and performing their primary missions. In February 2025, General Guillot said in response to a question about readiness effects that while some military forces were operating in areas outside of their primary skill set, other personnel were performing in line with their training specialty. Congress could consider the long-term implications of continued military support to border operations on funding and readiness requirements.