Three more attempts to revive the plan were made after Operation Flash in early May, when Croatia captured a portion of western Slavonia previously controlled by the RSK. The first initiative, that began later that month, failed because the RSK demanded that the Croatian forces pull back from western Slavonia (which Croatia declined to do). The second attempt failed simply because neither party wanted to negotiate. The final round of negotiations where the Z-4 Plan was proposed by international diplomats occurred in early August, when a major Croatian attack against the RSK seemed imminent. This time RSK leadership seemed more willing to negotiate based on Z-4 plan, but Croatia presented its own demands (including immediate replacement of the RSK with a Croatian civilian government), which were refused. On 4 August, Croatia launched Operation Storm, defeated the RSK and effectively ended the political process which led to the creation of the Z-4 Plan.