'Regular forces' does not refer to the United States' standing military forces.
Executive summary
The claim "'Regular forces' does not refer to the United States' standing military forces" is inconsistent with the weight of historical, legal, and lexical sources: across dictionaries, military practice, and counsel briefs the phrase has traditionally meant the standing, professional military (the "Regular Army" or active-duty armed forces) rather than civilian law‑enforcement agencies [1] [2] [3] [4]. That established meaning is precisely the dispute driving litigation over 10 U.S.C. § 12406, where advocates for a broader reading have advanced policy arguments but face substantial textual and historical counterweights [5] [6] [7].
1. The ordinary meaning: “regular forces” as the standing, professional military
Contemporary reference works and encyclopedias define a "regular army" or "regular forces" as a nation's permanent, full‑time professional armed forces—the standing army distinct from reserve components, militias, or irregulars—language found in Wikipedia entries, dictionary definitions and lexica that treat "regular" as the antonym of part‑time or irregular service [1] [2] [3] [4] [8].
2. Historical and statutory context ties the term to the federal military
Legal history and statutory interpretation show Congress and commentators using "regular forces" to distinguish federal standing troops from state militias or National Guard units not yet federalized; amici and historians marshaled this background in recent briefs arguing that the 1908 formulation now codified at 10 U.S.C. § 12406 referred to the standing, professional military—what contemporaries called the "Regulars"—and not to civilian federal law‑enforcement agencies [6] [7].
3. Case law and courtroom stakes: why the meaning matters now
The Supreme Court’s request for supplemental briefs in Trump v. Illinois—asking whether "regular forces" refers to the United States military—reflects the immediate legal consequence: an expansive reading could let failures of nonmilitary federal agencies be treated as the precondition for deploying and federalizing state militias under the Insurrection Act’s statutory descendant, while the narrower, traditional reading confines that trigger to the standing armed services [5].
4. Competing interpretations: political and operational arguments for a broader reading
Those urging a broader gloss—cited in briefing and public argumentation—frame "regular forces" as including "regular federal law enforcement forces" or other federal agencies deployed to execute federal laws, an interpretation motivated by perceived enforcement gaps and policy aims to make the National Guard available when other federal actors are allegedly unable to act [5]. That position is pragmatic and politically consequential, but it departs from the long‑standing lexical and historical usage emphasized by scholars and some courts [6] [7].
5. International and contractual uses show variance, not universality
Notably, outside the U.S. or in contractual definitions, "regular forces" has been defined variably—the term can be broadened by statute or contract to include police, intelligence, or other security services in specific legal texts (for example, LawInsider definitions in other jurisdictions)—which demonstrates that meaning can be specified differently by lawmakers, but does not erase the dominant U.S. usage tying "regular forces" to the standing military [9].
6. Bottom line and limits of available reporting
On the record provided, the best-supported conclusion is that "regular forces" in U.S. legal and lexical practice refers to the standing, professional military; arguments that the phrase excludes the military and instead denotes civilian federal agencies are minority positions advanced for policy and litigation purposes and remain contested in courts and scholarship [1] [2] [6] [5] [7]. This reporting does not—and cannot yet—predict how the Supreme Court will resolve the dispute or how Congress might amend the statute to alter the term’s legal effects.