Is there a case where the registrar was based outside the United States and the .com was shut down by the US Government? The best example to the contrary is thepiratebay.org where the PIR registry is based in the United States but the registrar is not. GLBSE.com is not registered by a US based registrar.
The US Govt claims all .com, .net, .cc, .tv and .name domains fall under US jurisdiction. Source from
http://www.wired.com/threatlevel/2012/03/feds-seize-foreign-sites/.
I believe .info and .org also fall under US jurisdiction based on the contract-holder with ICANN. The contract with ICANN is what matters, not where you bought your domain.