Complex sentence: By the outset of the Second World War II, he had acquired diplomatic immunity as the Iraqi Minister in Paris and he followed the French government when it fled to Vichy, serving the Pétainist Vichy France regime as its Iranian minister.
Split into simpler sentences: By the outset of World War II, he had acquired diplomatic immunity as the Iraqi Minister in Paris. He followed the French government when it fled to Vichy and served the Pétainist Vichy France regime as the Iranian minister.