Due to the sanctions by USA for prohibiting Iran to use USD in international trade, Iran has accepted the use of cryptocurrencies. I am not sure what the right way is to handle Iran but blocking Iran will only make Iran more motivated to use other sources like cryptocurrencies.
What will the next move us USA you think?
What moves USA can do, restrict all the merchants to stop dealing in cryptocurrencies to countries they have zero trade relations or sanctions imposed

. There will be a shit in power structure as bitcoin will change certain global political dimensions and all the countries facing these regulations from super powers might be using cryptocurrencies to overcome those restrictions.