M. Todd Bennett is an associate professor of history at East Carolina University and the author of "One World, Big Screen: Hollywood, the Allies, and World War II."

Chairman Charles E. Grassley (R-Iowa) arrives for a July Senate Judiciary Committee hearing titled “Oversight of the Foreign Agents Registration Act and Attempts to Influence U.S. Elections.” (Drew Angerer/Getty Images)

After a decades-long hiatus, propaganda is back in the news.

America is awash in Russian propaganda aimed at tipping the scales in our political process. Just this weekend, #SchumerShutdown, the Republican label blaming Democratic Senate Leader Charles E. Schumer for shuttering the federal government, was the top trending hashtag promoted by Russian propaganda bots on Twitter. But Russian propaganda isn’t limited to Twitter and hashtags; in some cases, it’s cloaked as legitimate media, like RT America.

The U.S. Department of Justice recently announced that RT America must comply with the Foreign Agents Registration Act (FARA) — this after U.S. intelligence concluded that the Russian television network participated in the attempt by Russia’s state-run propaganda apparatus to influence the 2016 U.S. presidential election. In the face of inaction by President Trump, The Washington Post editorial board joined those calling for additional measures to safeguard domestic politics from the “armies of bots” and other forces spreading disinformation online.

Shadowy agents. New media. Democracy imperiled. It is all so unnerving in part because it has happened before. In fact, much of what Americans know today about propaganda — what it is, how to combat it and why — stems from an earlier time when concern about “un-American” forces warping domestic politics reached a fever pitch.

As U.S. authorities consider how to prevent future interference, it may be instructive to revisit the run-up to World War II, when Congress enacted FARA to serve as a first line of defense against foreign propaganda. The legislative history of the statute teaches that openness, the very thing that leaves democratic politics so vulnerable to outside manipulation, provides one of America’s best defenses against foreign propaganda.

Propaganda wasn’t always a dirty word. Its origins trace to the 17th-century Catholic Church and its effort to propagate the faith. Propaganda, in this sense, was simply the promotion of a particular point of view.

The benign nature of propaganda began to shift in the early 20th century. The prominence of British and German propagandists during World War I, and their blatant efforts to influence American opinion with claims and counterclaims, made Americans cautious about foreign meddling. But it took the weaponization of culture by totalitarian states such as Nazi Germany to give propaganda the pejorative, even sinister, connotation it has today.

In 1937, as Adolf Hitler prepared to expand in Europe and swastika-carrying members of the German-American Bund goose-stepped in cities and towns along America’s Eastern Seaboard, a special committee of the U.S. House of Representatives issued its final report about the threat foreign propaganda posed. Chaired by future Speaker of the House John McCormack (D-Mass.) and Samuel Dickstein (D-N.Y.), the committee found “[i]ncontrovertible evidence” showing that agents of foreign governments were actively spreading materials designed “to foster un-American activities, and to influence the external and internal policies of this country.” These efforts, added the report, violated “the democratic basis of our own American institutions of government.”

A forerunner of the House Committee on Un-American Activities (HUAC) — which would eventually be corrupted and stained by the fervor to root out Communists — the McCormack-Dickstein Committee saw how totalitarian regimes in Italy and Germany had gained power, in part, from their control over the media. During the 1930s, it was Nazi Germany that had mastered such tactics to sell its radical ideology to the masses.

The Nazi propaganda machine was untruthful, hateful and manipulative. It was also the most sophisticated and effective in the world, which made it particularly dangerous. Joseph Goebbels employed the latest communications technology, including radio and motion pictures, and uber-stylish choreography to target the emotions of the Great Depression’s economically disadvantaged “forgotten man.”

Secrecy cloaked propaganda, which troubled congressional investigators. Often people who appeared to be just another voice in the crowd were, in fact, agents paid by the Nazi regime to spread lies and inflame passions. Such devious tactics tested preexisting “liberal faiths, especially in the ideas of informed discourse, a rational public, the eventual triumph of truth, and good government,” writes media scholar Brett Gary.

To defend the nation, the McCormack-Dickstein Committee did not recommend outlawing alien propaganda. Banning speech, even speech deemed un-American, risked further compromising democratic norms, civil libertarians warned. To balance liberty and security, the committee instead proposed disclosure.

The Foreign Agents Registration Act of 1938 required people acting as agents of foreign principals to file a registration statement with the U.S. government spelling out the registrant’s relationship with, and activity on behalf of, the principal. A 1942 amendment also required agents to submit for inspection copies of “political propaganda,” defined as any form of communication that sought to “prevail upon, indoctrinate, convert, induce, or in any other way influence” American citizens on behalf of a foreign government. Such material had to be “conspicuously marked.” Willful failure to comply with the law was punishable by a fine, imprisonment or both.

Supporters believed that FARA would shine “the spotlight of pitiless publicity” to expose the secretive world of foreign propaganda. Facts, they argued, would arm the public against manipulative efforts. Openness also aided U.S. investigators, who could trace foreign propaganda networks by poring over the registration statements filed by foreign agents.

Disclosure worked, at least in the short term. Justice Department prosecutors won more than 50 cases tried under the act from 1939 to 1944. Legal defenses were coupled with a counteroffensive led by the U.S. Office of War Information to fight enemy ideas with “democratic propaganda” — that is, emotional but also factual messaging geared toward selling the American way of life. Such information warfare helped to defeat the Nazi propaganda menace, shoring up homeland security as the United States and its allies marched toward victory in World War II.

FARA remained on the books after 1945, but Nazism’s defeat had rendered the law all but obsolete. In 1966, Congress updated the measure to protect the integrity of the American decision-making process from lobbyists, public relations counsels and those who sought to influence U.S. policies to the satisfaction of foreign clients. Legislators updated it again in 1995, striking “political propaganda,” a disreputable term that seemed archaic due to its association with the sins of totalitarians past, in favor of “informational materials,” a euphemism that better reflected on the more straightforward way in which most contemporary lobbyists and publicists went about their business.

FARA fell out of use nonetheless. Stopping foreign propagandists fell far down the Justice Department’s priority list. Loose enforcement enabled self-reporting agents to skirt the law, as indicated by numerous performance reviews conducted over the years by governmental as well as nongovernmental watchdogs. In the process, FARA became the “toothless” law critics know it as today.

Over most of its 80-year history, FARA has proved unable to regulate even the slow-moving flow of media such as pamphlets and books. As such, the statute, a legal relic of a bygone technological era, hardly seems adaptable to the Information Age of today when data crosses international borders at light speed. Yet FARA’s successful use of disclosure rather than censorship during World War II suggests how a democracy can effectively wage information warfare, despite the vulnerabilities that come with openness.

Disclosure may be imperfect. But if history is any guide, more speech, not less, is America’s not-so-secret weapon.