On 22 July 1995, Tuđman and Izetbegović signed the Split Agreement, binding both sides to a "joint defence against Serb aggression". Tuđman soon put his words into action and initiated Operation Summer '95, carried out by joint forces of HV and HVO. These forces overran the towns of Glamoč and Bosansko Grahovo in western Bosnia, virtually isolating Knin from Republika Srpska and FR Yugoslavia.