@daedrix the take on this is wrong.
Mastercard and Visa are the ones laying on the pressure because they can.
MC and Visa are just "data transmission" companies while American banks themselves are not allowed to do this - unless the transaction is specifically illegal.
In America, banks are legally required to allow ANY transaction, unless it breaks the law. So if I buy porn by writing a check or giving my routing number and account, it doesn't matter if its considered "offensive" to the lobbyists or the board of directors, the bank has to support the transaction because of the law. But MC and Visa are not bound by this law.
So we need to go after the Japanese government and the American government to make these "data companies" legally required to support any transaction, as long as it's not illegal.