Retired Marine Gen. James Cartwright arrives at U.S. District Court in Washington on Monday. (Pablo Martinez Monsivais/Associated Press)

The Obama administration Justice Department has investigated three senior officials for mishandling classified information over the past two years but only one faces a felony conviction, possible jail time and a humiliation that will ruin his career: former Joint Chiefs of Staff vice chairman General James E. Cartwright. The FBI’s handling of the case stands in stark contrast to its treatment of Hillary Clinton and retired General David Petraeus — and it reeks of political considerations.

Monday marked a stunning fall from grace for Cartwright, the man once known as “Obama’s favorite general,” who pleaded guilty to the felony charge of lying to the FBI during its investigation into the leaking of classified information about covert operations against Iran to two journalists. His lawyer Greg Craig said in a statement that Cartwright spoke with David Sanger of the New York Times and Dan Klaidman of Newsweek as a confirming source for stories they had already reported, in an effort to prevent the publication of harmful national security secrets.

Under his plea deal, Cartwright could face up to five years in prison and a $250,000 fine. Last year, Petraeus cut a deal with the Justice Department after admitting he had lied to the FBI and passed hundreds of highly classified documents to his biographer and mistress Paula Broadwell. He pleaded guilty to a single misdemeanor of mishandling classified information and was sentenced to two years probation and a $100,000 fine.

Clinton was not charged at all for what FBI Director James B. Comey called “extremely careless” handling of “very sensitive, highly classified information.” Comey said that although there was “evidence of potential violations of the statutes regarding the handling of classified information,” the FBI’s judgment was that no reasonable prosecutor would have filed charges against Clinton or her associates.

FBI Director James Comey testified on July 7 at a U.S. House of Representatives hearing on presumptive Democratic presidential nominee Hillary Clinton's decision to use a personal email server while serving as Secretary of State. (Peter Stevenson/The Washington Post)

“There is a lack of proportion just based on the facts that one figure, Cartwright, is getting severely punished and others so far have escaped the process,” said Steven Aftergood, director of the project on government secrecy at the Federation of American Scientists. “He is being singled out for prosecution and public humiliation. It’s an implicit rebuttal to those who argued that other senior officials such as Clinton or Petraeus got off scott free or got too light of a sentence.”

[Hillary Clinton fails the ABCs of handling classified information]

In its statement announcing the conclusion of its three-year investigation of Cartwright, the FBI emphasized that his prosecution showed that the Justice Department is willing to go after senior officials.

“The FBI will continue to take all necessary and appropriate steps to thoroughly investigate individuals, no matter their position (emphasis added), who undermine the integrity of our justice system by lying to federal investigators,” said Assistant Director in Charge Paul Abbate.

That statement reveals that the FBI is trying address public criticism that it gives senior officials like Petraeus and Clinton special and favorable consideration, Aftergood said.

“They seem to be trying to make a policy point,” he said. “The Justice Department would say they are not influenced at all by policy or political considerations. In the real world, of course they are influenced.”

The announcement of the charges and Cartwright’s guilty plea came on the same day the FBI released documents that allege the State Department, through Undersecretary of State for Management Patrick F. Kennedy, offered the FBI a “quid pro quo” for altering the classification of documents found on Clinton’s private email server. The State Department maintains Kennedy made no such offer. The FBI said no deal was struck but it would investigate the issue.

Still, the FBI’s unprecedented release of documents related to its Clinton investigation shows the Bureau is keenly aware of the public criticism of Comey’s decision not to recommend any charges. And the mere fact that Clinton had the State Department, along with an army of lawyers, negotiating with the FBI over the investigation shows that the playing field is not even for the targets of such investigations. Petraeus, for his part, had several top U.S. senators publicly calling on the FBI to exonerate him before he cut his deal.

Cartwright, by contrast, was short on high-profile Washington friends. He had long ago run afoul of his two Pentagon bosses, Defense Secretary Robert Gates and Joint Chiefs Chairman Adm. Mike Mullen, who never forgave him for going around the chain of command to join with Vice President Joe Biden to present Obama with an alternate plan for the Afghanistan troop surge in 2009.

Cartwright’s greatest mistake was not talking to reporters or lying about it; he failed to play the Washington game skillfully enough to avoid becoming a scapegoat for a system in which senior officials skirt the rules and then fall back on their political power to save them.

I interviewed Cartwright on his way out of the Pentagon in 2011, after he was passed over for the job of Joint Chiefs chairman. A high-stakes whispering campaign about an alleged affair made the appointment politically difficult for Obama. Cartwright confirmed to me (on the record) that the president had promised him the job but later reneged due to the smear campaign. From that point on, Cartwright was a pariah to many of the Very Important People in Washington’s national security elite.

[The FBI’s misstep on Clinton’s emails]

One notable difference between Cartwright’s case and that of Clinton and Petraeus was the fact that Cartwright was the subject of a leak investigation. There’s no evidence Clinton or Petraeus’s actions led to the public disclosure of classified information. The Obama administration has prosecuted twice as many leakers as all previous administrations combined. The mostly low-level prosecutions have often resulted in harsh prison sentences. For example, Army Private Chelsea Manning is serving 35 years at Fort Leavenworth.

Cartwright’s prosecution allows the Justice Department to say even senior-level leakers face consequences.

“General Cartwright violated the trust that was placed in him by willfully providing information that could endanger national security to individuals not authorized to receive it and then lying to the FBI about his actions,” Acting Assistant Attorney General Mary McCord said in a statement. “With this plea, he will be held accountable.”

But McCord’s statement begs the question: Will the other Stuxnet leakers be held accountable? No one has suggested that Cartwright was the primary source of the Stuxnet disclosures. According to emails obtained by the conservative action group Freedom Watch, Sanger had meetings on Iran with several other high-profile administration officials, including National Security Adviser Tom Donilon, Deputy Secretary of State Bill Burns and even Clinton herself. There’s no evidence of any other Stuxnet leak investigations of high-level officials.

Today, Petraeus maintains his status as a revered figure and sought-after thought leader. He works for a consulting firm, sits on several boards, teaches at a university, continues to advise the White House on national security and appears frequently on television. Clinton may go on to be the president of the United States.

In his best-case scenario, Cartwright could avoid prison time but will be saddled with a felony conviction that will bar him from most money-making opportunities. In the worst-case scenario, he could be getting released from prison around the same time Clinton finishes her first term.

In his statement taking responsibility for lying to the FBI, Cartwright asserted his motivations were patriotic. “My only goal in talking to the reporters was to protect American interests and lives; I love my country and continue to this day to do everything I can to defend it.”

Can Clinton or Petraeus plausibly make the same claim regarding their indiscretions?