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History of the North Atlantic Treaty

After the Second World War, Europe found itself divided - physically and politically - with Eastern Europe controlled by the Soviet Union. The UK and nine other countries from Western Europe, as well as the United States and Canada, signed the North Atlantic Treaty to counter the risk that the Soviet Union would try to extend its control to other parts of the continent.

The founding members of Nato - the UK, Belgium, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, and the US and Canada - committed themselves to coming to each other's defence in the event of a military attack against any of them.

What gave the agreement strength was that it bound North America to the defence of Western Europe. This was a clear message to the Soviet Union that the US would step in if it tried to push further west into Europe. The Nato agreement also ensured that the national defence policies of all the Nato countries would gradually integrate, making the union stronger.

During the 1950s the role of Nato became more important, as the potential threat from the Soviet Union did not recede. Turkey and Greece joined the Alliance in 1952, followed a year later by West Germany. At the request of some European governments, US military bases were set up in Europe to further deter any threat from Moscow.

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Nato's role today

The role of Nato remained largely unchanged until the fall of the Soviet Union and the liberation of Eastern Europe. By the 1990s many people believed that Nato was no longer needed. The 'old enemy' was no longer a threat and many countries reduced military spending.

However, Nato found a new role as new conflicts emerged in the Balkans and parts of the former Soviet Union. These wcooars strengthened the alliance between Nato countries and reinforced the view that collective defence and co-operation was still the best way to guarantee security.

Spain joined in 1982, and the Czech Republic, Hungary and Poland joined in 1999. Seven more countries joined in 2004: Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia and Slovenia. Albania and Croatia joined in 2009, bringing the number of Nato countries to its present total of 28.

Nato has helped to end conflicts in Bosnia and Kosovo, and to head off a civil war in the former Yugoslav Republic of Macedonia. Nato-led forces are now helping to bring stability to Kosovo, Afghanistan, Iraq and Darfur.

Nato's functions

Membership of Nato is central to UK defence policy. Nato's formally stated functions are to:

• help provide security and stability in the Euro-Atlantic area
• provide a transatlantic forum for member states to consult on issues of common concern
• deter and defend against any threat to the territory of any Nato member state
• contribute to crisis management and conflict prevention on a case-by-case basis
• promote partnership, co-operation and dialogue with other countries in the Euro-Atlantic area

How Nato works

Every decision taken by Nato is based on consensus. This means that every country in Nato must agree before a decision can be taken. Although this can lead to lengthy discussion, it has two advantages. Firstly, the sovereignty and independence of each member country is respected, and secondly, when a decision is reached it has the full backing of all the Nato countries. This helps to strengthen the role of Nato.

The most important decision-making body in Nato is the North Atlantic Council, on which every member country sits. The current British representative is Mariot Leslie, CMG. She is supported by civil servants from the Foreign Office and the Ministry of Defence, and military officers from all three defence services. Foreign ministers from member countries meet at the Council at least twice a year.

Nato is headed by a Secretary General - a senior international statesman from one of the member countries. Anders Fogh Rasmussen from Denmark was appointed to the role in 2009.

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