Drop Shipping Offshore Hosting

In doing some research on offshore hosting I am wondering about its usefulness. The seizures of the domains of several very large gambling sites is a good example. They were all hosted offshore and in places where gambling is fine and they were still shut down.

I've read that it doesn't matter if your domain is hosted offshore with even though you are hosted offshore the registry of the domain is not and comes under the the umbrella of ICANN and subsequently are under US authority.

Can anyone clear this up for me?