One reliable bipartisan characteristic of U.S. leaders is an obsession with shaping the foreign policy narrative and concealing any information that contradicts their version of events. Indeed, many of them harbor the desire to prosecute anyone who leaks classified material that exposes blunders, lies or crimes. Two events in the past few weeks demonstrate that the desire to squash such disclosures is running at high tide: the attempt to extradite and prosecute WikiLeaks founder Julian Assange on espionage charges, and President Trump’s angry outburst accusing the New York Times of “treason” for its story disclosing U.S. cyberattacks on Russia’s power grid.

The Trump administration seems eager to go after troublesome journalists—a course that previous administrations generally have avoided since the U.S. Supreme Court decision in the 1971 Pentagon Papers case. The actual extent of that decision’s protection typically has been overstated, however. The Court rejected the administration’s bid for prior restraint—the use of censorship to bar publication–but did not explicitly address the question of whether authorities could prosecute journalists once a story using classified documents appeared. Individuals who leak items to the press remained as vulnerable as ever to prosecution for espionage, but members of the press have enjoyed de facto immunity. Officials seemed wary that post-publication attempts to prosecute press outlets might run afoul of the courts as well.

With the attempt to prosecute Julian Assange, that situation threatens to change dramatically. There actually have been warning signs for some time, especially during Barack Obama’s administration. The government named Fox News reporter James Rosen as an “unindicted co-conspirator” in an espionage case against his source. Similarly, the administration asserted that it had the right to prosecute New York Times reporter James Risen, who had printed leaked classified information, although it chose not to take that step. Those were ominous signals.

I discuss the importance of the Assange case for preserving press freedoms in a new article in the July-August issue of the American Conservative. The government’s strategy is especially insidious. Federal officials argue that whatever the relevance of the Pentagon Papers precedent, it doesn’t apply in this case because Assange is not a real journalist engaged in legitimate journalism. Instead, he is allegedly a co-conspirator with Chelsea Manning and other individuals who illicitly leaked classified information. Therefore, the argument goes, he has committed espionage, and any legal protections that legitimate journalists might enjoy should not extend to his behavior. John Demers, the Justice Department’s assistant attorney general for National Security, stated that thesis explicitly. “Julian Assange is no journalist,” Demers sneered.

Unfortunately, when British authorities arrested Assange in April, many American establishment journalists cheered the move. Such attitudes partly reflect resentment at an upstart player who has broken several blockbuster stories. Legacy publications are less than thrilled about blogs and other online competitors that have sprouted during the twenty-first century. Many prominent mainstream publications also exhibit special resentment toward Assange because he expresses open animosity toward U.S. foreign policy, while those publications usually have backed Washington’s often blundering overseas commitments and initiatives. Whatever their motives, such outlets are adopting a dangerously misguided stance. Successfully prosecuting Assange and WikiLeaks for espionage would be a devastating threat to a free and independent press in the United States.

We must not allow the government to decide who is or is not a “legitimate” journalist. Yet that is exactly Washington’s ploy in the Assange case. If federal prosecutors prevail with that argument and eventually convict him of espionage, the implicit protections that the Pentagon Papers ruling has afforded the press will be severely diluted. Only legacy publications friendly to the national security bureaucracy could then count on government restraint—and as Trump’s outburst against the New York Times for its Russia cyberwar article demonstrates, even that expectation could become quite fragile. Obstreperous online outlets and their writers would routinely find themselves under threat of criminal prosecution if they dared publish a negative story based on classified information. At a minimum, there would be a pronounced chilling effect on (already insufficient) foreign policy dissent in the media.