The Justice Department has opened an investigation into the leak of classified Pentagon documents appearing to detail Ukraine’s combat capabilities, its potential vulnerabilities and NATO’s broad efforts to help repel Russia’s invasion, the agency said Friday, as the U.S. government raced to determine how the material surfaced online and what value it may hold for the Kremlin.

The department said in a statement that it was in communication with the Pentagon and had begun an investigation, but had no further comment.

Confirmation of the investigation came as senior U.S. officials realized the scope of the documents leaked was wider than initially thought.

Earlier Friday, The Washington Post obtained dozens of what appeared to be photographs showing classified documents dating to late February and early March that range from worldwide intelligence briefings to tactical-level battlefield updates and assessments of Ukraine’s defense capabilities. They outline a wealth of information about the Ukrainian and Russian militaries, and also include highly sensitive U.S. analyses about China and other nations. The materials also reference highly classified sources and methods that the United States uses to collect such information, alarming U.S. national security officials who have seen them.

A Pentagon spokeswoman, Sabrina Singh, said in a brief statement that the matter is under review, but declined to address when officials there first became aware of the leak, and how damaging the Biden administration considers the disclosure to be.

One U.S. defense official, who like others spoke on the condition of anonymity to discuss the Pentagon’s preliminary understanding of the leak, said that many of the documents appear to have initially have been prepared over the winter for Gen. Mark A. Milley, chairman of the Joint Chiefs of Staff, and other senior military officials, but they are available to many other U.S. personnel and contract employees with the appropriate security clearances.


It was unclear who may have posted the materials online, this person said, adding that hundreds – if not thousands – of people had access to them. The source of the leak, the official said, “could be anyone.”

The material that appeared online includes photographs of documents labeled “Secret” or “Top Secret,” and began appearing as early as March 1 on Discord, a chat platform popular with gamers, according to a Washington Post review.

On Wednesday, images showing some of the documents began circulating on the anonymous online message board 4chan and made their way to at least two mainstream social media platforms, Telegram and Twitter. In some cases, it appears that the slides initially circulated on Discord were manipulated. For instance, one image features combat casualty data suggesting the number of Russian soldiers killed in the war is far below what the Pentagon publicly has assessed.

The disclosure, first reported Thursday by the New York Times, coincides with an expansive effort by the United States and NATO to arm and train Ukrainian units for an anticipated push this spring to reclaim Russian-occupied territory in the east and south. There were immediate concerns that the leak could complicate that plan, as the documents appear to reveal how much Western military weaponry and other equipment had arrived on the battlefield, how many Ukrainian soldiers are trained to use it, and how Ukraine has arrayed its air defenses to stop an onslaught of Russian missiles.

Another potentially sensitive data point is the rate at which NATO-supplied howitzers are burning through the 155 mm shells they fire. The documents appear to describe incoming shipment flows and projections outlining how fast the Ukrainians would run out if shipments were impeded. The Pentagon has refused to disclose such insights publicly and only vaguely describes how much artillery ammunition it provides.

The documents also include battlefield assessments, including for Bakhmut, the Ukrainian town where Russian and Ukrainian forces have been stalemated for months, locked in a ferocious grinding artillery campaign that has left thousands dead.


While the documents do not contain specific battle plans, the material is “incredibly helpful” to the Kremlin, said Dmitri Alperovitch, chairman of Silverado Policy Institute, a think tank. “It literally has order of battle information – detail about the units that will be involved [in the forthcoming counteroffensive], their manning, equipment and training levels. . . . That information can be extremely beneficial for putting up a defense.”

The documents appear to have been drawn from multiple reports and agencies, and concern matters than Ukraine. Two pages, for example, are purportedly a “CIA Operations Center Intelligence Update,” and includes information about events concerning Russia, Hungary and Iran.

“We are aware of the posts and are looking into the claims,” a CIA spokesperson said in a statement.

Rachel E. VanLandingham, a former Air Force attorney and expert on military law, said that whoever is responsible for the leak “is in a world of hurt.” Such breaches, she said, constitute “one of the most serious crimes that exist regarding U.S. national security.”


Alex Horton, Dalton Bennett, Shane Harris and John Hudson contributed to this report.

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