The Espionage Act of 1917 is a United States federal law enacted on June 15, 1917, roughly two months after the United States entered World War I.1) It criminalizes the unauthorized obtaining, retention, or communication of information related to “national defense” when done with intent or reason to believe the information will be used to harm the United States or aid a foreign nation, and contains separate provisions addressing interference with military recruitment and operations. Originally codified in Title 50 of the U.S. Code, most surviving provisions are now found in Title 18 (18 U.S.C. § 792 et seq.).2) The law's text has not changed substantially regarding its core “national defense information” provisions since enactment, but its application has shifted markedly over time, from wartime suppression of anti-war speech to modern prosecutions of government leakers and, in one case, a publisher. Whether the Act's language reaches conduct beyond espionage in the conventional sense - and whether it is compatible with the First Amendment as applied to leakers, whistleblowers, and journalists - remains contested; see espionage-act-1917-scope-viewpoint and espionage-act-1917-first-amendment-debate.
The Act's central provisions, principally 18 U.S.C. §§ 793 and 794, remain active law and are the primary vehicle the federal government uses to prosecute unauthorized disclosure or retention of classified national defense information.3) Key provisions include criminal liability for gathering or transmitting defense information to aid a foreign nation or injure the United States, for retaining national defense documents without authorization, and for communicating such material to persons not entitled to receive it. The original Act also contained a provision criminalizing “false statements” intended to interfere with military operations or promote enemy success, and provisions on insubordination and disloyalty within the armed forces; a related and more sweeping set of speech restrictions, commonly called the Sedition Act of 1918, amended the Act for roughly two years before its repeal in 1921.4)
In its first use, the Department of Justice and the Postmaster General applied the Act broadly against anti-war and socialist speech; the Supreme Court upheld convictions under it in 1919 in three companion cases, articulating the “clear and present danger” test in an opinion by Justice Oliver Wendell Holmes Jr.5) That standard was later effectively superseded, outside the Act itself, by the stricter “imminent lawless action” test of *Brandenburg v. Ohio* (1969).6) For an extended account of the Act's drafting, the wartime speech prosecutions, and the post-war Red Scare enforcement under Attorney General A. Mitchell Palmer, see espionage-act-1917-history.
Since the 1970s the Act has increasingly been used against government insiders who disclose classified information to journalists rather than against persons working on behalf of a foreign power, beginning with the 1971 indictment of Daniel Ellsberg over the Pentagon Papers.7) The frequency of such prosecutions rose sharply after 2001 and again under the Obama administration, which brought Espionage Act charges against more alleged leakers than all prior administrations combined, including Chelsea Manning, Edward Snowden, Thomas Drake, Jeffrey Sterling, and John Kiriakou.8) In 2019 the Trump administration indicted WikiLeaks founder Julian Assange, marking the first use of the Act against a publisher rather than a leaker or government employee; Assange pleaded guilty to a single count in June 2024 as part of a plea agreement.9) The statute contains no explicit public-interest or whistleblower defense, and motive has not been recognized as a defense in prosecutions to date.10) Whether the Act can or should be applied to journalists and publishers, as opposed to the government employees who leak to them, is a live and unresolved question; see espionage-act-1917-press-freedom-controversy.