The North Atlantic Treaty organisation is an association of independent states based on the principle of collective defence; it was founded on 4 April 1949 with the signing of the Washington Treaty. The Treaty established the joint defence of the NATO member countries, with an attack against one member country equalled to an attack against the whole Alliance.

NATO has 28 member states: Albania, Belgium, Bulgaria, Canada, Croatia, Czech Republic, Denmark, Estonia, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxemburg, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Turkey, United Kingdom and USA.

In addition to this, NATO cooperates with numerous partner countries and other international organisations.

NATO activities are based on the common values of its member countries, which are:

Solidarity – NATO is an association of 28 North American and European states that aims to fulfil the provisions of the North Atlantic Treaty signed on 4 April 1949. One of the most important provisions of the Treaty says that an attack against one NATO member country is considered to be an attack against the whole NATO and that all the NATO member states will intervene in case of military conflict.

Freedom – under the North Atlantic Treaty, NATO has the main aim of protecting the freedom and security of its member countries with political and military means.

Security – NATO stands for the common values of its members; these include democracy, individual freedom of every person, rule of law and peaceful resolution of conflicts. NATO promotes these values in the Euro-Atlantic area.

Trans-Atlantic unity – the Alliance is the embodiment of trans-Atlantic unity which is an inalienable bond between the security of America and that of Europe. The Alliance stands for all efforts made to defend the common interests of member countries.

Estonia is a member of the NATO since 29 March 2004. Active membership in the NATO remains a long-term strategic priority of the Estonian security and defence policy, since it allows effective participation in international security cooperation and is the most efficient guarantee for the defence of the Estonian state.

Membership in the NATO and the European Union has assured Estonia’s security much better than ever, since the NATO and the EU help to ensure the stability of Estonia’s international status and its integration into the democratic Western world. Membership in the NATO ensures a credible military deterrent and collective defence. Like other NATO member countries, Estonia prioritises the development of mobile and sustainable armed forces and improvement of the capacity to contribute to international peace operations.

International security environment is going through a variety of changes which has brought along a broadening of the idea of security, with security questions having become an issue in fields where they did not arise before, i.e. the new threats (terrorism, energy security and cyber security). The tasks for ensuring security thus change with the times for the NATO as well as for Estonia.