The US isn't a big fan of consensus and will probably chart out its own path. Seeing the way the US has in the past tried to bully global banks into toeing its line, I suspect its laws will try to cover cryptocurrency transactions beyond its borders. In which case, most crypto institutions will avoid the US and US citizens like the plague.
That's true. The US does often act unilaterally. Dealing with US customers implies serious risk from a business standpoint. But it's also a massive market, which is why there will always be institutions seeking their business. Either you have deep pockets for compliance and regulatory risk (like Coinbase), or you operate in the grey/black markets.
I'll be curious to see how organizations like the WTO decide on international cryptocurrency services. For example, in spite of all its takedown and seizure attempts, the WTO ruled against the US government in the Bodog case. An Antiguan license confers the legal right to offer gambling services to the US market, regardless of what the US says. The US authorities dropped all felony charges against Calvin Ayre in that case. So they're not omnipotent.