The International Civil Aviation Organization (ICAO) is headquartered in Montreal, Canada, due to a combination of post-WWII geopolitics and Canada's historical role in aviation. In 1946, Montreal was selected as the permanent seat during the first assembly of PICAO (the provisional body). At the time, Montreal was a major global hub; its geographic position meant that early long-range flights often had to stop there for refueling. Strategically, Montreal was a perfect "compromise" location between the interests of the United Kingdom and the United States. Canada offered vast, safe spaces for aviation research and was a leading manufacturer of aircraft at the time. Furthermore, the Canadian government provided significant financial subsidies and a dedicated building to house both ICAO and IATA (International Air Transport Association), cementing the city's status as the "Civil Aviation Capital of the World." In 2026, this legacy continues, with Montreal hosting the majority of the world's international aviation regulatory bodies, supported by the city's bilingual nature and its proximity to the United Nations headquarters in New York.