March 23, 2026

Jack Thorlin (University of Arkansas) has posted The Original Defensive War Power (57 pages) on SSRN.  Here is the abstract:

In justifying recent military actions lacking congressional authorization, presidents have invoked a “defensive” war power to justify everything from attacks on drug boats to air battles over Israel to the bombing of Iran’s nuclear facilities. The Department of Justice Office of Legal Counsel (OLC) has enabled these operations through an expansive interpretation of the President’s power to wage a defensive war. OLC grounds this expansive presidential authority in President Washington’s 1790 offensive against the Wabash Indians and Jefferson’s 1801 naval operations against Barbary pirates. This Article shows that OLC has fundamentally misread both episodes, and that a third largely ignored conflict provides further confirmation of a restrictive unilateral presidential war power.

Examining contemporaneous debates in all three conflicts—the Northwestern Confederacy War, the First Barbary War, and Andrew Jackson’s 1818 seizure of East Florida—this article recovers a narrower original understanding of the defensive war power. The original doctrine only authorized the President to (1) repel an actual invasion; or (2) fight a war already declared against the United States by a foreign power. OLC’s interpretation is not a faithful application of Founding-era precedents, but an adaptation to social, technological, and geopolitical changes that have lowered the political and practical costs of unilateral action. This Article closes by considering the implications of the original defensive war power for interbranch cooperation on judicial review in national security matters.

My earlier thoughts on this issue are here: The President’s Power to Respond to Attacks. I think the article’s framing of the issue is generally correct, so that the issue as applied to (for example) the current situation in Iran is whether Iran had previously attacked the United States or otherwise declared itself to be at war with the United States.

Posted at 6:07 AM