If the US wants to block a given .ru it can do so, it's just a question of forcing ISPs to block it. I don't know what the current legislation in the US is for ISPs and what they are obliged or not to do when the government asks them to. But at the end of the day the traffic has to pass through some medium to reach Russia, and neither you or me or our ISPs laid down network cables across the Atlantic or put communication satellites in orbit.
What's the obsession with .com? Well there is already a lot invested in .com and the US holds all of this power. You can't just tell everyone to "switch to .ru what's the big deal?". That was a good question to ask 10 years ago. Right now it's fact and the question is how to distribute the power of .com.
What I'm suggesting will create anarchy in TLDs, that is true. But in practice nothing really has to change. The registry for .uk becomes authoritive for .com in the UK, the registry for .fr becomes authoritive for .com in France, and so on. Then they just need to agree on a process for change management between them, and a way to resolve disputes. When disputes cannot be resolved there will be fragmentation, which I believe is better then one side, the one that happens to control the TLDs, forces their laws and opinions on the other.
In practice 99.9% there won't be any issues, and the rest of the time it will be around politics or intellectual property. But it is exactly this potential of fragmentation and anarchy that will guarantee the global neutrality of the "global" TLDs.