The North Atlantic Treaty Organisation (NATO), also called the North Atlantic Alliance, the Atlantic Alliance or the Western Alliance, is an international organisation for collective security established in 1949, in support of the North Atlantic Treaty signed in Washington, DC, on 4 April 1949. Its headquarters are located in Brussels, Belgium. Its other official name is the French equivalent, l’Organisation du Traité de l’Atlantique Nord (OTAN) (English and French being the two official languages of the organisation).
The Treaty of Brussels, signed on 17 March 1948 by Belgium, the Netherlands, Luxembourg, France, and the United Kingdom, is considered the precursor to the NATO agreement. This treaty established a military alliance, later to become the Western European Union. However, American participation was thought necessary in order to counter the military power of the Soviet Union, and therefore talks for a new military alliance began almost immediately. These talks resulted in the North Atlantic Treaty, which was signed in Washington, DC on 4 April 1949. It included the five Treaty of Brussels states, United States, Canada, Portugal, Italy, Norway, Denmark and Iceland. Three years later, on 18 February 1952, Greece and Turkey also joined. Because of geography, Australia and New Zealand missed out on membership. In place of this, the ANZUS agreement was made by the United States with these nations. The incorporation of West Germany into the organisation on 9 May 1955 was described as “a decisive turning point in the history of our continent” by Halvard Lange, Foreign Minister of Norway at the time.  Indeed, one of its immediate results was the creation of the Warsaw Pact, signed on 14 May 1955 by the Soviet Union and its satellite states as a formal response to this event, firmly establishing the two opposing sides of the Cold War.
During most of the duration of the Cold War, NATO maintained a holding pattern with no actual military engagement as an organisation. On 1 July 1968, the Nuclear Non-Proliferation Treaty opened for signature: NATO argued that its nuclear weapons sharing arrangements did not breach the treaty as US forces controlled the weapons until a decision was made to go to war, at which point the treaty would no longer be controlling. Few states knew of the NATO nuclear sharing arrangements at that time, and they were not challenged. On 30 May 1978, NATO countries officially defined two complementary aims of the Alliance, to maintain security and pursue détente. This was supposed to mean matching defences at the level rendered necessary by the Warsaw Pact’s offensive capabilities without spurring a further arms race. However, on 12 December 1979, in light of a build-up of Warsaw Pact nuclear capabilities in Europe, ministers approved the deployment of US Cruise and Pershing II theatre nuclear weapons in Europe. The new warheads were also meant to strengthen the western negotiating position in regard to nuclear disarmament. This policy was called the Dual Track policy. Similarly, in 1983–84, responding to the stationing of Warsaw Pact SS-20 medium-range missiles in Europe, NATO deployed modern Pershing II missiles able to reach Moscow within minutes. This action led to peace movement protests throughout Western Europe. The membership of the organisation in this time period likewise remained largely static, with NATO only gaining one new member in 30 May 1982, when newly democratic Spain joined the alliance, following a referendum. Greece also in 1974 withdrew its forces from NATO’s military command structure, as a result of Greco-Turkish tensions following the 1974 Cyprus dispute; Greek forces were however readmitted in 1980. In November 1983, a NATO manoeuvre code-named Able Archer 83, which simulated a NATO nuclear release, caused panic in the Kremlin. Soviet leadership, led by ailing General Secretary Yuri Andropov became concerned that US President Ronald Reagan may have been intending to launch a genuine first strike. In response, Soviet nuclear forces were readied and air units in Eastern Germany and Poland were placed on alert. Though at the time written off by US intelligence as a propaganda effort, many historians now believe Soviet fear of a NATO first strike was genuine.
The end of the Cold War, the dissolution of the Warsaw Pact in 1991, removed the de facto main adversary of NATO. This caused a strategic reevalution of NATO’s purpose, nature and tasks. In practice this ended up entailing a gradual (and still ongoing) expansion of NATO to Eastern Europe, as well as the extension of its activities to areas not formerly concerning it. The first post-Cold War expansion of NATO came with the reunification of Germany on 3 October 1990, when the former East Germany became part of the Federal Republic of Germany and the alliance. This had been agreed in the Two Plus Four Treaty earlier in the year. To secure Soviet approval of a united Germany remaining in NATO, it was agreed that foreign troops and nuclear weapons would not be stationed in the east, and also that NATO would never expand further east. On 28 February 1994, NATO also took its first military action, shooting down four Bosnian Serb aircraft violating a UN no-fly zone over central Bosnia and Herzegovina. NATO air strikes the following year help bring the war in Bosnia to an end, resulting in the Dayton Agreement. Between 1994 and 1997, wider forums for regional cooperation between NATO and its neighbours were set up, like the Partnership for Peace, the Mediterranean Dialogue initiative and the Euro-Atlantic Partnership Council. On 8 July 1997, three former communist countries, Hungary, the Czech Republic, and Poland, were invited to join NATO, which finally happened in 1999. On 24 March 1999, NATO saw its first broad-scale military engagement in the Kosovo War, where it waged an 11-week bombing campaign against what was then the Federal Republic of Yugoslavia. The conflict ended on 11 June 1999, when Yugoslavian leader Slobodan Milošević agreed to NATO’s demands by accepting UN resolution 1244. NATO then helped establish the KFOR, a NATO-led force under a United Nations mandate that operates the military mission in Kosovo. Debate concerning NATO’s role and the concerns of the wider international community continued throughout its expanded military activities: The United States opposed efforts to require the UN Security Council to approve NATO military strikes, such as the ongoing action against Yugoslavia, while France and other NATO countries claimed the alliance needed UN approval. American officials said that this would undermine the authority of the alliance, and they noted that Russia and China would have exercised their Security Council vetoes to block the strike on Yugoslavia. In April 1999, at the Washington summit, a German proposal that NATO adopt a no-first-use nuclear strategy was rejected.
After the September 11th attacks
The expansion of the activities and geographical reach of NATO grew even further as an outcome of the September 11th attacks. These caused as a response the provisional invocation (on September 12) of the collective security of NATO’s charter — Article 5 which states that any attack on a member state will be considered an attack against the entire group of members. The invocation was confirmed on 4 October 2001 when NATO determined that the attacks were indeed eligible under the terms of the North Atlantic Treaty. The eight official actions taken by NATO in response to the attacks included the first two examples of military action taken in response to an invocation of Article 5: Operation Eagle Assist and Operation Active Endeavour. Despite this early show of solidarity, NATO faced a crisis little more than a year later, when on 10 February 2003, France and Belgium vetoed the procedure of silent approval concerning the timing of protective measures for Turkey in case of a possible war with Iraq. Germany did not use its right to break the procedure but said it supported the veto. On the issue of Afghanistan on the other hand, the alliance showed greater unity: On 16 April 2003 NATO agreed to take command of the International Security Assistance Force (ISAF) in Afghanistan. The decision came at the request of Germany and the Netherlands, the two nations leading ISAF at the time of the agreement, and all 19 NATO ambassadors approved it unanimously. The handover of control to NATO took place on 11 August, and marked the first time in NATO’s history that it took charge of a mission outside the north Atlantic area. Canada had originally been slated to take over ISAF by itself on that date.
Like any alliance, NATO is ultimately governed by its 26 member states. However, the North Atlantic Treaty, and other agreements, outline how decisions are to be made within NATO. Each of the 26 members sends a delegation or mission to NATO’s headquarters in Brussels, Belgium. The senior permanent member of each delegation is known as the Permanent Representative and is generally a senior civil servant or an experienced ambassador (and holding that diplomatic rank). Together the Permanent Members form the North Atlantic Council (NAC), a body which meets together at least once a week and has effective political authority and powers of decision in NATO. From time to time the Council also meets at higher levels involving Foreign Ministers, Defence Ministers or Heads of Government and it is at these meetings that major decisions regarding NATO’s policies are generally taken. However, it is worth noting that the Council has the same authority and powers of decision-making, and its decisions have the same status and validity, at whatever level it meets. The meetings of the North Atlantic Council are chaired by the Secretary General of NATO and, when decisions have to be made, action is agreed upon on the basis of unanimity and common accord. There is no voting or decision by majority. Each nation represented at the Council table or on any of its subordinate committees retains complete sovereignty and responsibility for its own decisions. The second pivotal member of each country’s delegation is the Military Representive, a senior officer from each country’s armed forces. Together the Military Representatives form the Military Committee, a body responsible for recommending to NATO’s political authorities those measures considered necessary for the common defence of the NATO area. Its principal role is to provide direction and advice on military policy and strategy. It provides guidance on military matters to the NATO Strategic Commanders, whose representatives attend its meetings, and is responsible for the overall conduct of the military affairs of the Alliance under the authority of the Council. Like the council, from time to time the Military Committee also meets at a higher level, namely at the level of Chiefs of defence, the most senior military officer in each nation’s armed forces. The NATO Parliamentary Assembly is made up of legislators from the member countries of the North Atlantic Alliance as well as 13 associate members.
NATO’s military operations are directed by two Strategic Commanders, both senior U.S. officers assisted by a staff drawn from across NATO. The Strategic Commanders are responsible to the Military Committee for the overall direction and conduct of all Alliance military matters within their areas of command. Before 2003 the Strategic Commanders were the Supreme Allied Commander Europe (SACEUR) and the Supreme Allied Commander Atlantic (SACLANT) but the current arrangement is to separate command responsibility between Allied Command Transformation (ACT), responsible for transformation and training of NATO forces, and Allied Command Operations, responsible for NATO operations world wide. The commander of Allied Command Operations retained the title “Supreme Allied Commander Europe (SACEUR)”, and is based in the Supreme Headquarters Allied Powers Europe (SHAPE) located at Casteau, north of the Belgian city of Mons. This is about 80 km (50 miles) south of NATO’s political headquarters in Brussels.