Devarim 16:18 appoint judges and officers (police) within all your gates (cities) which Hashem is giving you, according to your tribes. And they shall judge the people with righteous right ruleing (good Judges governing local cities).
Create international Sanhedrin with supreme halachic authority over any other existing claimants to halachic authority thus making you the one true form of Judaism?
How would the international nazarene beit din/sanhedrin thingy prevent Mr. John Doe, from reading that verse and deciding HE needs to create an international sanhedrin with supreme halachic authority? And whose would be the real one? Is it a "I was here first" situation? Is it a who ever happens to have the most Torah knowledge situation?