NATO’s Eastward Expansion On April 4, the North Atlantic Treaty Organization marks 75 years since its inception. The alliance was established by the North Atlantic Treaty that was signed in Washington in 1949 by foreign ministers from 12 countries: Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the UK, and the U.S.. There are now 32 #NATO members, including Sweden, which joined the organization on March 7. Bosnia and Herzegovina also aspires to become a member. To join the organization, a country must execute a membership action plan that is tailored to its individual needs, have no territorial disputes and bring its armed forces in line with the alliance's standards.