NORTH ATLANTIC TREATY ORGANIZATION
NATO is a collective security alliance formed in 1949 as an anti-Soviet military alliance. It initially consisted of 10 European countries, and the United States and Canada. Today it consists of 30 countries, including Belgium (1949), Canada (1949), Denmark (1949), France (1949), Iceland (1949), Italy (1949), Luxembourg (1949), Netherlands (1949), Norway (1949), Portugal (1949), United Kingdom (1949), United States (1949), Greece (1952), Turkey (1952), Germany (1955), Spain (1982), Czech Republic (1999), Hungary (1999), Poland (1999), Bulgaria (2004), Estonia (2004), Latvia (2004), Lithuania (2004), Romania (2004), Slovakia (2004), Slovenia (2004), Albania (2009), Croatia (2009), Montenegro (2017), North Macedonia (2020). Many of the countries that joined NATO after 1991 were former Soviet Republics or Warsaw Pact countries.
"Security in our daily lives is key to our well-being. NATO’s purpose is to guarantee the freedom and security of its members through political and military means. (It) promotes democratic values and enables members to consult and cooperate on defense and security-related issues to solve problems, build trust and, in the long run, prevent conflict. (It) is committed to the peaceful resolution of disputes. If diplomatic efforts fail, it has the military power to undertake crisis-management operations. These are carried out under the collective defense clause of NATO's founding treaty - Article 5 of the Washington Treaty or under a United Nations mandate, alone or in cooperation with other countries and international organizations.
NATO's official response to Russia's aggression and links to other stories can be found here.
Beyond NATO: A New Security Architecture for Eastern Europe by 