Ambassadors cannot be arrested sued or taxed in the country where they at serving because of?

Ambassadors cannot be arrested, sued, or taxed in the country where they are serving due to diplomatic immunity, a principle established under international law, specifically the Vienna Convention on Diplomatic Relations of 1961. This immunity is designed to ensure that diplomats can perform their duties without interference from the host country, thereby fostering international relations and diplomacy. It protects them from legal actions and taxation to maintain the dignity and functionality of diplomatic missions.