> If Putin can control the US from his third world backwater, maybe he deserves to be in power.
Destruction and construction are asymmetric. It takes far less effort to destroy something than it does to create something and things that are delicately balanced can be toppled with only a small application of force.
> What makes him so good that the world's most advanced country is powerless against him?
Internal divisions, magnified to make them seem larger than they really are.
> Is it because Russians are such good hackers?
No, it is because when it comes to propaganda Russia has a leg (or rather several legs) up compared to the USA. The USA would do something like 'voice of America', the Russians would carpet bomb the nation with their version of the story, a history to corroborate their version and a continuous barrage of flak to get in the way of intelligent discussion.
And anybody that managed to get some kind of opposition going would as a rule never be heard from again.
Fortunately in America that stage has not yet been reached, let's hope it will never happen.
> Taiwan, Mexico and so on - fair enough.
Ok
> But overall it is not as if all the countries in the world were friends and only Trump is shaking things up now.
No, but they weren't all-out enemies either and Trump is pushing in that direction (not Taiwan). Even in Europe, one of the USA's staunchest allies when it comes to operations abroad there is strong talk of distancing because of the new perceived instability of America.
> There were always conflicts of interest, new trends that shift power (like oil and phracking), military interventions and what not.
Yes, but just like Hitler found out: you can't fight wars on all fronts at once.