Which legal authorities (congressional authorization, self-defense, NATO) were cited for strikes under Biden?
Executive summary
The Biden administration has most commonly invoked the president’s Article II commander‑in‑chief powers, cited the 2001 and 2002 Authorizations for Use of Military Force (AUMFs) as permissive/“ancillary” authority to defend U.S. forces, and relied on procedural reporting under the War Powers Resolution — not fresh, specific congressional declarations of war — as the principal legal rationales for strikes during his term [1] [2] [3]. Public reporting in the sources reviewed does not show NATO authorization being cited for Biden‑era strikes; if any NATO linkage exists, the reviewed reporting does not document it (limitation: no source provided).
1. Article II and the president’s claimed self‑defense authority
Administration statements and legal practice under Biden reflect the longstanding executive claim that Article II of the U.S. Constitution empowers the president, as commander‑in‑chief, to order limited military force to defend U.S. personnel and interests without prior congressional approval; Reuters and other analyses note that the White House framed strikes as defensive responses to attacks on U.S. bases and vessels, a position premised on Article II authority [1] [3]. Legal scholars and civil‑liberties groups dispute the scope of that claim — arguing presidents have over‑relied on Article II to bypass Article I’s war‑making role — but the administration has repeatedly invoked Article II in its 48‑hour War Powers reports and public statements [3] [4].
2. Reliance on the 2001 and 2002 AUMFs as “ancillary” authority
Congressional Research Service reporting and multiple summaries show the executive branch treating the 2001 and 2002 AUMFs as flexible statutory bases: the administration frames those statutes as primary authorizations for some offensive operations and as secondary authority to defend U.S. forces or partners — a doctrine the executive has called “ancillary defenses” when used to justify strikes against groups linked to Iraq, Syria, Yemen, or the Red Sea [2] [5]. The CRS and other observers point out the administration’s 48‑hour notifications often cite these AUMFs alongside Article II powers, indicating a combined statutory and constitutional rationale rather than a discrete new congressional authorization [2] [5].
3. The War Powers Resolution: reporting and temporal constraints
When operations are not premised on explicit congressional authorization, the administration has used the War Powers Resolution’s reporting regime — filing reports within 48 hours that describe circumstances, authority, and estimated scope — to notify Congress and to assert its legal footing, while acknowledging the WPR’s 60‑day limitation on hostilities absent congressional approval [1] [2]. Critics and watchdogs, including litigation and FOIA efforts, argue the WPR’s mechanisms are insufficient to substitute for affirmative congressional authorization and say the administration has sometimes sought to “keep Congress informed” rather than obtain prior consent [4] [1].
4. International law claims and the distinction from congressional authorization
Legal commentators and institutions (e.g., West Point/Lieber Institute) have assessed certain Biden strikes as consistent with international law’s self‑defense norms and the law of armed conflict when the administration frames actions as necessary and proportionate to specific attacks on U.S. forces, while other scholars dispute those international law conclusions or the factual predicates for self‑defense [6] [7]. Separately, neither international‑law reasoning nor claims of proportionality substitute for domestic congressional authorization under Article I, a point central to critics who demand clearer statutory mandates or repeal of the older AUMFs [7] [8].
5. NATO authorization: not documented in the reviewed reporting
The sources provided do not identify NATO authorization or invoking NATO collective defense (Article 5) as a legal basis cited by the Biden administration for the strikes discussed; reporting instead centers on Article II, AUMFs, and War Powers filings (limitation: no source provided that connects NATO authorization to these strikes) [1] [2] [5]. If NATO participation or invocation existed for a specific operation, that linkage is not present in the material supplied and would require separate documentation.
6. Political context, competing narratives and implicit agendas
Supporters portray these legal rationales as necessary to protect Americans and allies quickly; critics frame the same authorities as executive overreach that circumvents Congress and the framers’ war‑declaring role, a tension reflected in FOIA litigation, congressional objections, and calls to repeal or replace the 2001/2002 AUMFs [4] [5] [8]. The executive’s dual reliance on constitutional Article II power plus residual AUMF authority lets it assert both independent and statutory justifications — a posture that preserves flexibility but invites sustained legal, political, and judicial scrutiny [2] [3].