By JANE MAYER

As soon as The New Yorker published the story of one aggressive leak prosecution by the Obama Justice Department, the news was topped by a second. Today, William Welch II, the same federal prosecutor who is pressing espionage charges against Thomas Drake, sparked a new showdown against the press. In a surprise move in another case, Welch issued a subpoena aimed at forcing James Risen, a national-security correspondent in the Washington bureau of the Times, to testify against a former C.I.A. officer who is accused of leaking national-security secrets to him. The subpoena is expected to pit the freedom of the press to cover highly sensitive intelligence issues against the government’s authority to define what must remain secret in order to protect national security.

The case in question involves a book that Risen wrote, “State of War,” in which he described a failed effort by the C.I.A. to sabotage Iran’s nuclear-weapons program. Jeffrey Sterling, a former C.I.A. officer, is facing trial on ten felony charges relating to the leak of the information. (He has pleaded not guilty.) Risen, along with Eric Lichtblau, another Times reporter, also wrote a 2005 news story exposing the Bush Administration’s warrantless domestic-surveillance program. Risen has been a target of federal leak prosecutions ever since.

Sterling’s lawyer, Edward MacMahon, described the subpoena of Risen as part of a campaign in which the Obama Administration has pursued leakers in much the same way the Bush Administration did: “Eric Holder’s every bit as aggressive a prosecutor as John Ashcroft. He just has more friends in the media,” McMahon said. “If John Ashcroft had brought any of these cases, there would have been a whirlwind of ‘Shame on you!’”

Under current Department of Justice procedures, the attorney general himself must sign off on all subpoenas of news reporters—an indication of how serious the underlying issues are in such constitutional clashes. “In issuing subpoenas to members of the media, the Department seeks to strike the proper balance between the public’s interest in the free dissemination of information and effective law enforcement,” Laura Sweeney, a spokeswoman for the D.O.J. told the Times. “We make every reasonable effort to attempt to obtain information from alternative sources before even considering a subpoena to a member of the press, and only seek information essential to directly establishing innocence or guilt.”

In a lengthy motion explaining the prosecution’s reasons for forcing a reporter to testify against a confidential source, Welch and the rest of the prosecution team described Risen as a “an eyewitness to the serious crimes”—the leak of national-security secrets. The testimony of Risen “is directly relevant to, and powerful evidence of, the factual issues that the jury must decide at trial,” the government argued. He is “commanded” to appear in the federal district court in Alexandria, Virginia, on September 12th, to testify in the case. Risen released a statement to the Times yesterday, saying that “I am going to fight this subpoena. I will always protect my sources, and I think this is a fight about the First Amendment and the freedom of the press.”

This is the government’s third effort at subpoenaing Risen in the case. He has been subpoenaed twice before, to appear before grand juries. He fought the first subpoena legally, and eventually it expired. The second time, the presiding judge, Leonie Brinkema, quashed the subpoena. Rather than accepting the judge’s position, the government has now subpoenaed Risen a third time, to testify in the trial itself.

One lawyer familiar with the case, who asked not to be identified, believes that the government is hoping to pressure the judge into making Risen testify, or else, if the judge refuses, hold her responsible should the case collapse. The lawyer also suggested that the government “just wants to put Risen in jail.”