Tor is in fact just a proxy chain consisting of 3 proxies. A good enough reason to do the paperwork can be enough to deanonymize a user (the link is valid assuming all the relays' ISPs store logs). Thus Tor users' need to worry about their anonymity highly depends on their threat model. (blowing up the WTC is most likely more motivating to do the paperwork than DDoSing your competency's site)
Once, I've read something about making a proxy chain distributed over countries that don't have a good political relationship in some very downvoted (because of the rest of the question) question here.
But the idea itself is interesting. If you've used Tor and for some reason the US government wants to have a friendly talk with you, using a proxy in countries with bad political relationship with the US, such as Russia, would make the paperwork really hard.
A good example of this US-Russia relationship is the Sci-Hub lawsuit:
Elsevier claims that Sci-Hub illegally accesses accounts of students and academic institutions to provide free access to articles through their platform ScienceDirect. The case is complicated by the fact that the site is hosted in St. Petersburg, Russia, making it difficult to target within the US legal system. [Source: https://en.wikipedia.org/wiki/Sci-Hub#Lawsuit]
Question (I admit this might be somewhat discussable/subjective): To what extent do the country choices affect users' anonymity (of course assuming you haven't hacked all the nuclear silos)? Is there any known case of paperwork beating a Tor circuit?
Note: I'm talking about knowing the user's Tor IP address only, nothing more. Not confirming their identity, but finding it.