4 Major Takeaways From the Leaked Pentagon Files

Several allegedly classified Pentagon files, totalling over 100 pages, were leaked on social media last week. The existence of the documents, which were found circulating on social media sites as early as Wednesday, was first reported by the New York Times and provide key details on issues ranging from battlefield vulnerabilities in Ukraine to intelligence on matters in allied countries around the world. The leak could be one of the most damaging public breaches of U.S. intelligence since thousands of classified documents were published through WikiLeaks.

Read More: The Mysteries of the Biggest Intel Leak in a Decade

Multiple offices, including the FBI and Department of Justice are working to identify the source of the leak. U.S. officials have not ruled out the possibility that pro-Russian elements were behind the leak. According to the New York Times, some of the documents were marked “for U.S. eyes only,” meaning that it is possible the documents were leaked by an American official.

It’s important to keep in mind that not all of the information may be reliable. Pentagon officials acknowledged that the leaks are indeed legitimate Department of Defense documents, but said that some appear to have been altered. For example, a modified document overstates American estimates of Ukrainian casualties and minimizes estimates of Russian troops killed. TIME could not independently verify the authenticity of the documents.

Here are four of the biggest takeaways from the leak.

Ukraine’s Air Force May Soon Collapse

Ukraine’s air defense faces serious challenges in upcoming months, documents reveal.

One alleged Pentagon slide dated Feb. 28 claims that, if Ukraine continues at current consumption rates, it will have completely depleted its stock of Buk missiles by April 13 and of S-300 missiles by May 3.

According to a map in another purported Pentagon presentation from the same day, by May, most of Ukraine’s critical national infrastructure outside Kyiv and two other areas in southwestern Ukraine will no longer have air-defense cover, with the number of unprotected critical sites jumping from six to more than 40.

The documents paint a different picture from the stance Biden took earlier that month. In a February 28th interview with ABC, President Biden rejected calls to send more fighter jets to Ukraine, saying Ukraine “doesn’t need F-16s now.”

The U.S. Holds Intelligence on Allies

Pentagon documents reveal that the U.S. has been spying on close allies, including South Korea and Israel.

One document mapped out an American assessment of scenarios that could lead Israel to provide weapons to Ukraine, in contrast to the country’s current policy. Another document detailed internal discussion among South Korea’s officials about the pressure they were under from Washington to help supply weapons to Ukraine.

A senior intelligence official described the leak as “a nightmare for the Five Eyes”—the five nations, that share intelligence information: the U.S., Britain, Australia, New Zealand and Canada.

The U.S. has Penetrated Russian Intelligence

The U.S. has a much clearer picture of Russian military operations than it does of Ukrainian planning, according to the New York Times. American intelligence has been able to obtain daily real-time warnings on the timing of Moscow’s strikes and even its specific targets. By exposing which Russian agencies the United States knows the most about, the leak could change this, as Russia could potentially cut off the sources of information the U.S. was able to access.

A Pro-Russian Hacking Group May Have Targeted Canada’s Energy Infrastructure

Zarya, a hacking group working under the guidance of Russia’s Federal Security Service, may have broken into Canada’s gas distribution network in February, compromising its I.P. address and damaging its infrastructure. The attackers had the capability to increase valve pressure, disable alarms and make emergency shutdowns of a gas distribution station.

“The F.S.B. officers anticipated a successful operation would cause an explosion at the gas distribution station, and were monitoring Canadian news reports for indications of an explosion,” the report said, noting that the hackers were not aiming to “cause loss of life” but economic damage.