Clash of Steel Operation Unthinkable German vs. British Starter SetFight exciting tank battles with many of the different tanks that were under development during and in the years after World War II. Can these super tanks really perform as expected? Clash of Steel lets you find out Operation Unthinkable is a complete starter set for Clash of Steel This set contains starter forces to play Germans and British Clash of Steel miniatures are 1 100 or 15mm in scale Models require assembly and painting.