Federal Constitution of the Swiss Confederation

¹A Can­ton may con­clude treat­ies with for­eign states on mat­ters that lie with­in the scope of its powers.

²Such treat­ies must not con­flict with the law or the in­terests of the Con­fed­er­a­tion, or with the law of any oth­er Can­tons. The Can­ton must in­form the Con­fed­er­a­tion be­fore con­clud­ing such a treaty.

³A Can­ton may deal dir­ectly with lower rank­ing for­eign au­thor­it­ies; in oth­er cases, the Con­fed­er­a­tion shall con­duct re­la­tions with for­eign states on be­half of a Can­ton.