The U.S. government released a report to prove that the Russian government was hacking, and apparently (I'm no IT security expert, so I rely on others) this is no more convincing than the infamous Iraqi WMD claims.
The attribution of hacking is almost impossible if the hacker isn't careless or incompetent. Nowadays you can use open wifi to access the internet. You can disrupt tracebacks by transmitting data in part through a 'private' directional radio communication to another computer that's connected to the hacker only by one time pad encrypted messages routed to various countries whose governments are not really cooperating with traceback requests.
So essentially you need multiple defectors or whistleblowers - insiders who give away the secret identity of the hacker.
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Personally, I don't doubt that teh Russian government is doing espionage, sabotage and manipulation through the internet.
it is a matter of principle to not believe a liar without solid evidence, though. The U.S. govenrment and in particular its intelligence services were exposed as liars too many times to be considered reliable sources. I don't hold the bar up very high; I don't believe the German government in regard to Russian hacking either. I believe the Russian overnment does hack, but I do not trust Western intelligence services' allegations.
These intelligence services serve first and foremost themselves, second they serve the political leadership. To serve the citizens is an odd idea to them. No doubt their personnel would disagree, but I think that's a problem of lacking self-awareness.
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Now what should we (Western countries) do in this affair?
- We could simply defend and endure whatever attacks bypass our defences. This is in itself a highly unsatisfactory (and politically unsustainable ) option.
- We could retaliate and be lucky enough to hit the right address. How could this possibly succeed? We cannot attribute attacks properly, so we wouldn't even learn if and when retaliation had convinced the offending government to cease its attacks. Much more likely we would enter a spiral of escalations.
- We could retaliate and be unlucky enough to hit the wrong address. Oops. Sadly, we wouldn't even notice our mistake.
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Maybe there is a way out. We could "retaliate" with something that's not offensive in itself, but rather something we could and may should do anyway. A government in Moscow lost a cultural war before*; we could defeat one such government again in a competition of quality of life.
That would happen to benefit us directly.
*: The Soviet Union lost the Cold War much more sdue to economic reasons and a long-hidden political brittleness than to the appeal of Jeans and McDonalds, but the attractiveness of Western life was most disconcerting to the East german governemnt. Nowadays most Russians are exposed to seeing how life is in the West as the East Germans whoe were able to receive West German TV stations..