Hackers associated with the Chinese military broke into a sensitive European Union communications network and stole thousands of secret documents, according to a story in the New York Times.

PLA Unit 61398 is being accused of copying secret diplomatic cables for years.  The hack was exposed by the security firm Area 1.

Euractiv:

More than 1,100 cables from the EU's COREU coded messaging system were supplied to the Times by security firm Area 1 after it discovered the breach, the newspaper said, adding that Area 1 investigators believed the hackers worked for the China's People's Liberation Army.

The cables include memorandums of conversations with leaders in Saudi Arabia, Israel and other countries that were shared across the European Union, according to the report.

One cable, the Times said, shows European diplomats describing a meeting between US President Donald Trump and Russian counterpart Vladimir Putin in Finland as "successful (at least for Putin)."

Another, written after a 16 July meeting, relayed a detailed report and analysis of talks between European officials and Chinese President Xi Jinping, who was quoted comparing Trump's "bullying" of Beijing to a "no-rules freestyle boxing match."

A third, from 7 March, shows Caroline Vicini, the deputy head of the EU mission in Washington, recommending the trade bloc's diplomats to describe the United States as "our most important partner" even as it challenged Trump "in areas where we disagreed with the US (e.g., on climate, trade, Iran nuclear deal)."

The hackers also infiltrated the networks of the United Nations, the American Federation of Labor and Congress of Industrial Organizations (AFL-CIO), and ministries of foreign affairs and finance worldwide, the report added.

A message dated 20 July quotes Ukrainian President Petro Poroshenko warning of illegal seizure of Ukrainian vessels in the Azov Sea (this scenario became reality on 20 November).

It's no surprise E.U. diplomats disdain Trump.  More to the point, what is the Western world going to do about PLA Unit 61398?

These guys have hacked governments, businesses, trade unions, and schools.  They have done it with impunity and no fear of punishment.  Short of going to war, what can be done?

In truth, not much.  Short of going to war – cyber-war, that is – sanctions are about the only option.  A cyber-war would only lead to more hacking by the Chinese of even more sensitive information.  We respond, they respond to our response, and so on, and before you know it, the hacking would become economically damaging.

No one wins a cyber-war, which is why we haven't engaged full-scale in one.  I'm sure we've engineered minor breaches of the Chinese government communications systems, but nothing that would provoke a major response.  About the best we can do is harden our networks and keep close tabs on Unit 61398.

They aren't going to stop attacking us anytime soon.