Switzerland has signed up as the15th member of the European Sky Shield Initiative (ESSI), a project which seeks to build a unified air and missile defence system across Europe.

• The system was initiated by Germany following Russia's invasion of Ukraine, and is designed to allow European countries to buy defence systems together, and train together.
• Armaments chief Urs Loher signed the declaration of accession making Switzerland the 15th member of Sky Shield.
• The project has been controversial in Switzerland, with opponents saying its involvement runs counter to the Swiss tradition of neutrality.
• Switzerland would also be able to withdraw its cooperation if a Sky Shield member became involved in a war.