The rise of George Robertson
	The role of secretary-general
	Robertson profile
	History: Alliance's Cold War roots
	Fast facts: Nato: Who, what, why

Western Europe and North America were locked in a battle with a Soviet regime committed to developing its military might. The allies needed a safety net to repel any form of aggression and to safeguard their freedom.

Their solution was the North Atlantic Treaty Organisation.

1949: The signing of the Nato Treaty

On 4 April 1949, 12 nations signed an agreement in Washington launching what was to become one of the world's most powerful alliances.

There were 10 European and two North American founder members: the US, Canada, Belgium, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal and the UK.

Nato members were united against Communism and had a common commitment to protection. The fundamental principle of the Treaty, which remains to this day, is Article 5: "an armed attack against one or more of them in Europe or North America shall be considered an attack against them all."

Military aims

From the start, Nato was open to accepting new members - and still is. Greece and Turkey joined the alliance in 1952, West Germany in 1955 (the reunited Germany officially acceeded in 1990) and Spain joined in 1982.

The original purpose of the grouping was to defend Western interests through the Cold War.

US troops were rushed to Western Europe in the 1950s to deter Soviet expansion

As Soviet satellite states signed up to the Warsaw Pact, Europe and North America were left feeling they needed Nato protection more than ever.

A command system for possible war-time use was established and the Military Committee became a powerful body.

Huge funds were poured into back-up for Nato forces - bases, airfields, depots and communication networks - to deter Soviet or Warsaw Pact expansion. US nuclear weapons were also stationed in Western Europe.

Faced with Soviet military strength, Nato was a security solution for the West

But the relationship between members was uneasy from the start. Striking the balance of power between Europe and the US began to cause problems as early as 1958.

The conflict came to a head in 1966 when French president Charles De Gaulle announced France would withdraw from the military structure in protest at dominance of US commanders. Nato forces were required to leave the country and headquarters were moved to Mons, Belgium.

Today, France remains only part the political structure of the alliance in case of "unprovoked aggression". It continues to emphasise the independence of its nuclear armoury and foreign policy.

A new era

Nato's greatest triumph is considered to be winning the Cold War. But the collapse of the USSR in 1991 and the sweeping away of the Iron Curtain left the allies with no obvious mission.

Nato tanks are used to bolster the defence of Western Europe

At summits in the early 1990s, members decided to rethink Nato's purpose and agreed a new direction. Officially, Nato is still a defensive body but in reality it has been trying to actively promote peace and stability.

At the 1991 Rome Summit, co-operation Central and Eastern European countries and the former USSR became a top priority.

Hungary, the Czech Republic and Poland became new members, moving Nato's borders an estimated 400 miles eastwards and adding an extra 350,000 servicemen. (They officially joined in March.)

Nato is facing a mid-life crisis on its 50th anniversary

The allies also gave Russia, their former enemy, a "voice but no veto". As US President Bill Clinton said: "These are new times. The veil of hostility between East and West is lifted."

In response to the decreased threat, numbers and readiness of Nato troops have been vastly reduced. This includes a 25% cut in the number of ground combat units and a reduction of over 45% in the peace-time strength of land forces in the Central Region.

Stockpiles of nuclear weapons are now only one-fifth of their total in 1990.

Dilemmas over Kosovo

The Kosovo crisis has given the alliance a new mission - and a political and military headache. Nato's response to Yugoslav President Milosevic was a product of its history - aiming to defend European countries' borders.

Secretary-General Javier Solana has helped steer Nato during the Balkans war

Nato's 50th anniversary summit this year was supposed to have been a celebration of its success. Instead, the alliance approached the anniversary summit facing its greatest challenge since it was formed.

This is a test of the Nato of the 21st century", said the US Secretary of State, Madeleine Albright.