Qatar can afford to be generous. It shares the world’s largest gas field with Iran, yet has just 300,000 citizens, making it the richest country per capita. In recent decades, Doha has transformed into a gleaming metropolis of global ambition where luxury cars crowd the streets and world-renowned architects have traced its futuristic skyline. An army of imported laborers is building stadiums and subway lines for the 2022 World Cup. But among fellow Arab states, Qatar’s image has been shaped by its contentious policy of come one, come all.