I can't remember which book I read it in, probably Dark Territory or Cyberspies, but the French were actually able to hack into the computers of the war room fo

I can't remember which book I read it in, probably Dark Territory or Cyberspies, but the French were actually able to hack into the computers of the war room for the joint chiefs and POTUS. They were so freaked out that they were able to do it (and worried that other foreign actors like the Chinese could do the same) that they informed the Americans, including how they did it. This was around twenty years ago, if I recall correctly. I think people underestimate European countries. Their less hostile, so people conclude that they lack capability, but they have 0days and cyberwarfare capabilities.