Regulating crypto is not hard because other countries are already regulating it, they can just follow the standard but most especially crypto being regulated will become centralized due to KYC which is the main policy.
If it's not that hard, why other countries didn't regulate it as well? The answers always rely on a kind of government that every country has, it might be
easy to others and might somewhat hard to most.
As for your question, it's impossible, there's no world government that has power to make decisions to other countries, crypto regulation will always be country-based.