The 40th Session of the triennial Assembly of the International Civil Aviation Organization (ICAO) took place in Montreal from 24 September to 4 October 2019. Notably, 2019 marked some important milestones in aviation: the 100th anniversary of the Paris Convention relating to the regulation of aerial navigation, signed on 13 October 1919; the 90th anniversary of the Warsaw Convention for the unification of certain rules relating to international carriage by air, signed at on 12 October 1929; and the 75th anniversary of the Convention on International Civil Aviation (Chicago Convention), signed on 7 December 1944. In the aviation context, 2019 was truly a year which called for reflection by the Assembly. The Assembly was also significant in its general theme of implementing the mantra of ICAO: ‘no country left behind’, through both a prospective and retrospective look at the performance of the Organization, as epitomised by a compelling working paper submitted by the United States at the Assembly. The article noted that ICAO’s traditional business practices may not keep up with the rapid pace in which the aviation industry is developing. It therefore exhorted ICAO to deliver through transparency for inclusiveness and better decision making; a positive work environment for high performance; leveraging partnerships for a better future; demonstration that it delivers what Member States need on a timely basis and uses all available resources for the greatest benefit to Member States and the aviation sector in a cost-effective manner; and the expansion of resources for delivery. This article examines this theme through the prism of some Resolutions adopted by the Assembly and inquires into what ICAO should do.