Stephen Kim, a former State Department expert on North Korea, leaves federal court in Washington on Wednesday after being sentenced. (Cliff Owen/AP)

A former State Department arms expert who leaked classified information to a Fox News reporter was sentenced Wednesday to 13 months in prison after a pointed courtroom debate about the Obama administration’s aggressive pursuit of unauthorized disclosures of top-secret information.

Stephen Jin-Woo Kim pleaded guilty in February to sharing classified information from an intelligence report on North Korea with reporter James Rosen, Fox’s chief Washington correspondent. Rosen was also targeted in the investigation by federal agents, who described him as a possible “co-

conspirator” in a bid to search his personal e-mails.

Criticism of the law enforcement tactics used in Kim’s case — and in another investigation involving the extensive collection of phone records of Associated Press journalists — led the Justice Department to revise its policies last summer for pursuing leaks of classified information to reporters.

The plea deal Kim signed in February called for a sentence of 13 months, and the length of his prison term was not in dispute ahead of the hearing Wednesday. But prosecutors and Kim’s legal team disagreed in court filings about the potential damage to U.S. national security from his disclosure.

Prosecutors said in court papers that Kim, a former senior intelligence adviser working on contract, “betrayed the trust of his country and placed our nation’s security at risk” by indirectly alerting North Korea to what U.S. intelligence officials “knew or did not know about its military capabilities and preparedness.”

Abbe D. Lowell, Kim’s attorney, said that his client “made a decision to cross a line” and that he “should have known better.” But Lowell added that Kim, who was born in South Korea, was motivated by a desire to bring more public attention to the threat posed by North Korea’s nuclear program.

The leak investigation was prompted by a Fox News report in June 2009 that said U.S. intelligence officials were warning that North Korea was likely to respond to a new round of sanctions by the United Nations with more nuclear tests. The report noted that the CIA warning was based on information from sources inside North Korea.

Rosen’s story was published online hours after a top-secret report was released to a restricted group of people within the intelligence community that included Kim.

Rosen did not respond to a request for comment Wednesday, and a company spokesman said Fox News would not comment.

The sentencing hearing turned into a somewhat heated discussion about the administration’s use of the Espionage Act to prosecute unauthorized government leaks. Under President Obama, the Justice Department has pursued more leak cases than all previous administrations combined.

Kim’s attorneys argued that their client’s limited disclosure was distinct from the troves of classified information released by Edward Snowden, a former National Security Agency contractor, and the State Department and military documents that former Army intelligence analyst Chelsea Manning, previously known as Bradley Manning, released to WikiLeaks. Kim was not a whistleblower with a political agenda who stole documents, his attorneys said.

Kim’s attorneys also called the Espionage Act a “blunt tool” meant for going after spies and suggested that prosecutors had unfairly targeted a relatively low-

level official for having a routine conversation with a reporter.

“His illegal conduct consisted solely of talking to a member of the news media with whom others in his office spoke as well,” the lawyers said.

“Government officials at every level speak with news reporters on a daily basis in Washington . . . [M]any of those conversations include the disclosure of classified information,” the lawyers said. “Yet few, if any, of those officials have paid the price that Mr. Kim has paid for a single conversation with a reporter.”

Assistant U.S. Attorney G. Michael Harvey said that the “everyone-does-it argument” was no excuse and that the law did not make a distinction between handing over documents or orally communicating top-secret information, as Kim did with Rosen.

Kim, Harvey said, “was motivated not by an altruistic purpose but by his own ego and desire for professional advancement.”

Before formally accepting the agreed-upon sentence of 13 months — far less than the maximum possible 10 years — U.S. District Judge Colleen Kollar-

Kotelly said Kim “did lose his moral compass” and had jeopardized his foreign policy career.

Standing at the courtroom lectern, Kim, 46, did not elaborate on his conduct. He called the past three years of pretrial litigation “extremely difficult” — both personally and financially — and said he is “dedicated to rebuilding my life” and starting over when released from prison.