Hacked European Cables Reveal a World of Anxiety About Trump, Russia and Iran

Hackers infiltrated the European Union’s diplomatic communications network for years, downloading thousands of cables that reveal concerns about an unpredictable Trump administration and struggles to deal with Russia and China and the risk that Iran would revive its nuclear program.

In one cable, European diplomats described a meeting between President Trump and President Vladimir V. Putin of Russia in Helsinki, Finland, as “successful (at least for Putin).”

Another cable, written after a July 16 meeting, relayed a detailed report and analysis of a discussion between European officials and President Xi Jinping of China, who was quoted comparing Mr. Trump’s “bullying” of Beijing to a “no-rules freestyle boxing match.”

The techniques that the hackers deployed over a three-year period resembled those long used by an elite unit of China’s People’s Liberation Army. The cables were copied from the secure network and posted to an open internet site that the hackers set up in the course of their attack, according to Area 1, the firm that discovered the breach.

Area 1 made more than 1,100 of the hacked European Union cables available to The New York Times. The White House National Security Council did not have an immediate comment on Tuesday.

The compromised material provides insight into Europe’s struggle to understand the political turmoil engulfing three continents. It includes memorandums of conversations with leaders in Saudi Arabia, Israel and other countries that were shared across the European Union.

But it also revealed the huge appetite by hackers to sweep up even the most obscure details of international negotiations.

The cyberintruders also infiltrated the networks of the United Nations, the A.F.L.-C.I.O., and ministries of foreign affairs and finance worldwide. The hack of the A.F.L.-C.I.O. focused on issues surrounding the negotiations over the Trans-Pacific Partnership, a trade deal that excluded Beijing.

Part of the United Nations material focuses on months in 2016, when North Korea was actively launching missiles, and appears to include references to private meetings of the world body’s secretary-general and his deputies with Asian leaders.