No major country including the US is going to allow itself to be forced to buy software without source code if required. Infact government contracts and even l

No major country including the US is going to allow itself to be forced to buy software without source code if required. Infact government contracts and even large private contracts require source code or escrow for continuity. Anything defense or critical infrastructure related will require code. So both from a technical, legal and national interest standpoint this can't pass the smell test. Vendors can always choose not to do business. Some large country may still try to arm twist smaller countries and do backroom deals with allies but on the whole its unlikely to pass because no one will sign it.