Norway and Iceland, neither of which are members of the European Union, have joined the Schengen group of countries. The Swiss will be watching closely to see how the effects of this move could influence their own bid to join the group in the future.
The Schengen agreement forms an integral part of the EU treaty and defines the union's policies on such issues as cross-border cooperation between police forces, border control and asylum. Last month, Switzerland declared that it would seek accession to the agreement in future negotiations with the EU.
As non-EU members, Norway and Iceland's association with the Schengen group of nations could set a precedent for Switzerland, also not a member of the EU. "I wouldn't say we're envious, but we're certainly interested to see how it will work out," Andrea Rauber, a specialist with the Foreign Ministry's Integration Office in Bern, told swissinfo.
There is a difference, however, between the Scandinavian states' membership of the group and Switzerland's hopes of joining. Norway and Iceland have been members of the Nordic Passport Union since the 1950s.
That grouping had abolished border controls long before the Schengen agreement, which first came into force as a separate, inter-governmental treaty between seven EU member states in 1991.
When the Schengen agreement was integrated into the EU treaty in 1997, the Nordic EU member states - Denmark, Finland and Sweden - made it a condition that border controls between them and Norway would not be reintroduced. Switzerland, however, won't be able to set any such conditions.
On Sunday, all five members of the Nordic Passport Union simultaneously became associates of the Schengen agreement, as well as of the related Dublin agreement that regulates asylum issues. Of the 15 EU member states, only the United Kingdom and Ireland are not party to those agreements.
In many ways, however, Switzerland's position would be similar to Norway's if it were to join the Schengen group. It would have to abolish fixed border controls with its EU neighbours but still maintain a workable system of customs checks, and it would have to accept policy changes within the Schengen regime without being able to take part in the decision-making process.
In spite of open borders, experts consider customs checks a minor problem. For example, Norway and Sweden rely on the honesty of travellers, who cross their common border, to declare goods at special offices.
A similar system could work along the Swiss-EU border, where only two percent of individual travellers currently undergo checks for undeclared goods. Commercial importers are billed electronically and pay customs taxes, independent of the physical cross-border movement of goods.
Opposition in Norway to the Schengen accession came mainly from civil rights groups, who feared an increase in identity checks throughout Norway's territory - a practice introduced in various EU states as a substitute for border controls. But the government in Oslo promised not to change its policy, and especially not to introduce identity cards, which are associated with Nazi occupation during the Second World War.
Andrea Rauber, of the Foreign Ministry's Integration Office, thinks the introduction of Schengen-style identity controls would be gradual in Switzerland. "Already, the tendency is not only to rely on fixed controls at the border. Rather, identity checks near the border have been improved.
"That's an on-going process that Switzerland has adopted regardless of any plans to become an associate to Schengen."
Rauber says the parallels with Norway's situation shouldn't be carried too far. "The main argument that speaks in favour of our joining the Schengen agreement is that Switzerland, due to its geographical position, is bound to be more integrated with its EU neighbours than Norway", she said.
by Markus Haefliger