The USA has a habit of projecting its own laws onto other nations.  If a bank dealing with bitcoin exchanges is locked out of the USA market it pretty much automatically gets locked out of the whole international market when the EU and allies follow. 

Take note of the recent sudden airspace refusal for the Bolivian president's plane from France, Portugal, Italy, etc.  Permission was suddenly, mysteriously revoked when the USA thought Edward Snowden might be on the plane.  The USA gets what it wants from its allies, and right now the USA is very interested in choking off the money supply to MtGox.  Where is MtGox located?  Japan.  All the USA has to do is remind Japan whose forces are stationed on their soil, and how said forces might not intervene in a conflict with China.  I am quite frankly surprised MtGox is still around today.