The advice of Switzerland's popular saint, Nicholas of Flüe (1417-87), "Don't get involved in other people's affairs" has been the hallmark of Swiss policy for nearly 500 years. The country has in effect been neutral since 1515, a status formally recognised and guaranteed by the great powers of Europe after the Napoleonic Wars in 1815.

Swiss neutrality thus has deeper roots than any of Europe's other major neutral states: Sweden (1815), Eire (1921), Finland (1948) and Austria (1955).

Neutrality is defined as non-participation in a war between other states. The rights and duties of neutral countries in time of war were laid down by the international community in 1907. In times of peace neutral states define their own rules, but take it for granted that they should stay outside military blocs, like NATO.

The status of neutrality has not only protected Switzerland from war, but has helped prevent the country from being torn apart when its different language communities might have been tempted to side with different belligerents in cases of conflict.

Since the end of the Cold War Switzerland has had to redefine its understanding of neutrality. It signed up to NATO's Partnership for Peace in 1996, stressing that it was motivated by the desire to promote peace and security and reserving the right to withdraw if it believed its neutrality was threatened.

The despatch of unarmed Swiss volunteers to Kosovo as part of peace keeping troops there after the 1999 war kept alive the debate over whether neutrality can be combined with an international role.

A referendum in June 2001 approved two key changes to the army's role. One allows Swiss soldiers to be fully armed when taking part in international peacekeeping missions, and the other permits them to take part in military training exercises with other countries. However, the bitter campaign showed the country was deeply divided on the issues, and the margin of victory was only two per cent.

The first armed Swiss peacekeepers arrived in Kosovo in October 2002.