WASHINGTON — A Minnesota woman who worked as a translator for the military in Iraq was charged on Wednesday with providing classified information to an Iran-backed militia group. Prosecutors said she intensified her espionage as tensions between the United States and Iran increased in recent months.
Prosecutors said the contractor, Mariam Taha Thompson, 61, revealed to a Lebanese man with ties to Hezbollah the names of foreign informants and details of the information they provided to the United States. The identities of informants who feed information to American spies overseas are among the government’s most closely held secrets, and law enforcement officials said Ms. Thompson endangered the lives of the informants as well as military personnel.
The officials suggested that the potential loss of classified information was grave and that the prosecution was one of the most serious recent counterintelligence cases they had seen.
“If true, this conduct is a disgrace, especially for someone serving as a contractor with the United States military,” John C. Demers, the assistant attorney general for national security, said in a statement. “This betrayal of country and colleagues will be punished.”
Ms. Thompson admitted to investigators that she illegally shared classified information with the Lebanese official, according to court papers. She was to appear in court on Wednesday afternoon in Washington.
The suspected leaks of classified information came at a critical time when Iranian proxy forces, like Hezbollah in Lebanon, were looking for ways to retaliate for the killing of Maj. Gen. Qassim Suleimani of Iran in a Jan. 3 drone attack that was a serious escalation of President Trump’s growing confrontation with Iran. General Suleimani was the architect of nearly every significant operation by Iranian intelligence and military forces over the past two decades.
Ms. Thompson’s purported espionage was discovered Dec. 30, days after American airstrikes on Hezbollah’s Iraqi arm and shortly before General Suleimani was killed.
As tensions with Iran increased in the final days of December, investigators discovered, Ms. Thompson’s activity on classified systems did as well. For six weeks, she accessed secret government files that contained the true names and photographs of American intelligence sources and government cables that outlined the information they provided to their handlers.
Investigators searched Ms. Thompson’s living quarters on Feb. 19 and discovered a handwritten note under her mattress listing the names of informants. The note, written in Arabic, also included a warning to a military target affiliated with Hezbollah whom prosecutors did not name and a request for the informants’ phones to be monitored.
According to government documents, Ms. Thompson had “a romantic interest” in the Lebanese man with whom she shared the classified secrets, and his nephew is a government official in Lebanon.
Ms. Thompson was charged with providing classified information, including the names of American foreign informants to a foreign government. F.B.I. agents arrested her at a military base in Erbil, Iraq, where she had been working on contract as a linguist.
The charges against her were the latest in a string of espionage cases as the government doubles down on its counterintelligence focus, seeking to stop the flow of American secrets overseas.
A little over a year ago, the government charged a former Air Force counterintelligence agent, Monica Elfriede Witt, with sharing secrets with the government of Iran, including the names of agents run by military intelligence whose cover was blown and the identities of her former co-workers.
Ms. Witt defected to Iran and, at least for now, remains beyond the reach of law enforcement officials.
But the government has brought to trial a number of other former intelligence officers, some of whom were charged with spying for China.
In November, Jerry Chun Shing Lee, a former C.I.A. officer, was sentenced to 19 years in prison for conspiring to deliver classified information to China. Mr. Lee’s disclosures occurred around the time that the C.I.A.’s informant network in China was collapsing, although prosecutors did not accuse him in court of involvement in the destruction of the spy network.
In May, another former C.I.A. officer, Kevin Patrick Mallory, was sentenced to 20 years after he was charged with spying for China. Mr. Mallory was accused of providing Beijing the names of sources that had helped the American government.
A third China case involved a contractor for the Defense Intelligence Agency, Ron Rockwell Hansen, who was sentenced in September to 10 years in prison.