After the French annexations of Bresse-Bugey (1601) and Franche-Comté (1678), the Helvetic Corps feared any new expansion of France in the direction of the Jura and the Alps. From this context emerged an original geopolitical project: to extend Swiss neutrality to the duchy of Savoy, a territory between France, Switzerland and Piedmont that the French army occupied in each war, in order to avoid any encirclement by this neighbour. From October 1703 to July 1704, during the War of the Spanish Succession, this project of neutrality was debated in Solothurn, Zurich and Baden in order to make Savoy into a «buffer territory» protecting the Helvetic Corps’ and Piedmont’ from military operations, or even into a «barrier» ensuring their independence. From diplomatic correspondence, this chapter intends to show how this project of Savoyard neutrality attempted to rebalance asymmetric relations with a hegemonic France (Louis XIV prevented any compromise between his adversaries, including Victor Amadeus II of Savoy) and the Swiss Cantons, mainly Bern, Zurich and Freiburg