Ukraine Confident in Spring Counteroffensive Despite Leaks, Pentagon Chief Says

Washington is seeking to assess the damage from an intelligence breach that could be one of the most significant leaks in recent history after images of seemingly highly classified U.S. documents publicly surfaced in early April. 

The unauthorized disclosures appear to provide details about Ukraine’s military, intercepted communications about U.S. allies such as Israel and South Korea, and details of American penetration of Russian military plans, among other topics.

U.S. officials have been reaching out to allies in recent days in an effort to contain any damage to Washington’s relationships around the world. “We have engaged with allies and partners at high levels in the past days,” Secretary of State Antony Blinken told reporters at a press conference with Mr. Austin and senior Filipino officials. 

Mr. Blinken spoke Tuesday with Ukrainian Foreign Minister Dmytro Kuleba to reaffirm support for the country. Messrs. Blinken and Austin declined to comment on specific actions Ukraine might take in an effort to recapture territory seized by Moscow.

 “They have a great plan to start, but only President [Volodymyr] Zelensky and his leadership really know the full details of that plan,” Mr. Austin said. “I have every confidence that they will do what great leaders do: They will fight the enemy and not be driven by a specific plan.”

Photo: Andrew Caballero-Reynolds/AFP via Getty Images

Mr. Austin said he was first briefed Thursday about the documents. 

The Wall Street Journal wasn’t able to independently authenticate the documents, but they contain enough detail to give them credibility. Defense officials have said they believe some of the documents could be authentic, though some also appear to have been altered.

Rep. Jim Himes, the top Democrat on the House Intelligence Committee, told the Journal that he expected to learn more about the leak when he returned to Washington from recess. 

“I don’t know how much is authentic,” said the Connecticut lawmaker. “It’s devastating. I just don’t see how this doesn’t end up meaning dead Ukrainians; it just breaks my heart. It’s hard to imagine what would motivate someone to do this.”

Mr. Himes said the reports of the documents being photographed and folded, perhaps to be smuggled from a secure facility, were strange and said it added to calls to reform how documents are secured.

“This is the first leak where you can sort of imagine fatalities as a result, quickly,” he added. “No leak is good but there’s no doubt in my mind that the only people scrutinizing this harder than the American [intelligence community] are the Russians.”

James Bamford, the author of several books on intelligence operations, said the leak of classified U.S. intelligence was the latest in several cases that reflected the government’s inability to secure its secrets. 

“I think the public needs to be aware of how poorly the intelligence community and the FBI counterintelligence people keep track of the intelligence that passes through the government each day,” he said in an interview with the Journal.

Mr. Bamford said the leak appeared “very arbitrary” in contrast with other high-profile cases such as Edward Snowden, who revealed to journalists secret details about the National Security Agency’s classified surveillance programs. 

“With Snowden, his focus was on what the NSA was doing domestically and illegally,” Mr. Bamford said.

By comparison, the current leak involved documents first posted directly to a messaging channel, with details about current operations in Ukraine. 

“It appears that there wasn’t any intention of any kind of filters,” Mr. Bamford said. 

—Natalie Andrews and Daniella Cheslow contributed to this article.