Ideally you would exploit bad diplomatic relations between nations to keep things running. Mutually non cooperative jurisdictions can actually be good for the internet. I do think the intention of the US gov is to completely control the internet though, copyright and DRM violations being a major motivation. As much as they claim they are about 'cooperation and collaboration' or some other nonsense, it's really about hard power.
the .to domain I believe can be seized but I don't know the conditions. .is can be seized but it is rare. The other thing is that treaties can be changed and the US can strong-arm people. Right now they work, I don't know if they always will.