Who signed the North Atlantic Treaty Organization (NATO)? July 11, 2023 – by admin 0A. 12B. 20C. 51D. 17NATO was created by 12 countries from Europe and North America on 4 April 1949.Since then, 19 more countries have joined NATO through nine rounds of enlargement (in 1952, 1955, 1982, 1999, 2004, 2009, 2017, 2020 and 2023).