Reactions to President Trump’s idea to create an “impenetrable cyber security unit” in collaboration with the Kremlin were still rolling in Monday morning, ranging from stunned to shocked to baffled. And in the end, even Trump himself didn’t think it was a very good idea.

Trump revealed Sunday that he discussed the possibility of such an unholy union with Russian President Vladimir Putin during their marathon meeting on the sidelines of the G-20 summit in Hamburg:

Following widespread ridicule and condemnation for suggesting the U.S. cooperate with a country accused of meddling in last year’s election, Trump rowed back just 12 hours later:

But would such a joint operation between two of the world’s leading proponents of the dark arts of intelligence, espionage, and cyberattacks be such a bad thing? Well, yes. Here’s why:

Russia hacked the election. Whether Trump believes it or not , the entire intelligence community (and much of the Republican Party) is convinced of this. Speaking about the proposed collaboration on NBC’s “Meet the Press” Sunday, Lindsey Graham said : “It’s not the dumbest idea I’ve ever heard, but it’s pretty close.” He added: “They did try to attack our election system. They were successful in many ways. The more you do this, the more people are suspicious about you and Russia.”

Russian hackers have stolen some of the NSA’s most powerful tools. A group calling themselves the Shadow Brokers appeared in the summer of 2016, leaking several hacking exploits which they say originated from the NSA’s elite Tailored Access Operations group. While the group denies it, ties to the Kremlin have been widely accepted at this point – in a recent attack on Ukrainian businesses by Russian hackers, one of the NSA’s tools was used.

Russian government hackers are already attacking the critical national infrastructure of the U.S. According to a report in the Washington Post Saturday, Kremlin-backed hackers recently penetrated the systems of U.S. nuclear power and other energy companies. While the hackers didn’t get near the core systems controlling operations at the plants, it’s a worrying development given how often Russian hackers have crippled Ukrainian electricity grids in recent years.

Russian cybercriminals — many in the pocket of the Kremlin — are costing U.S. companies and individuals tens of billions of dollars every year. One operation discovered last December — dubbed Methbot — was stealing up to $5 million every single day from U.S. brands and media companies. Despite spending huge amounts of money on protecting their systems, U.S. companies are still playing catch-up with criminals from Russia who are usually several steps ahead.

The U.S. is currently trying to get Russia to agree to extradite several high-profile criminals for major cyber attacks against U.S. companies, including the hackers behind the devastating Yahoo breach . The FBI’s top four most wanted cyber criminals are all Russian: Alexsey Belan , Dmitry Aleksandrovich Dokuchaev , Igor Anatolyevich Sushchin and Evgeniy Mikhailovich Bogachev .

Congress is trying to actively exclude Russian cybersecurity company Kaspersky Labs from from federal networks, believing that they are in collusion with the Kremlin. Eugene Kaspersky, the company’s mercurial founder and CEO, studied cryptography, programming, and mathematics at an academy operated by the KGB, the FSB’s Soviet-era predecessor, before going to work for the Ministry of Defense. Kapersky denies all allegations of collusion, recently offering to open up the company’s source code to lawmakers in Washington to prove his point. However documents seen by McClatchy suggest there is a link between the company and the Russian spy agency, the FSB. Given that Kaspersky would be likely at the center of any joint operation between Washington and Moscow, it would make it much tougher for Congress to blackball the company.

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