Though it was able to acquire a number of tanks through the international market, the republican government of the Oceanykan Federation saw itself cut from the outside world by the outbreak of World War 2, as all nations scrambled to form armoured units. In response, the government assembled an emergency industrial committee to design a new medium tank for the Council's armoured forces. The result was the Australian Cruiser Tank Mk. I "Sentinel", or AC1 Sentinel. By late 1941, republican factories were churning out these tanks in great numbers. Some consider the ability for the republican government to act quickly in these types of emergencies, a decisive factor in their eventual victory. However, the design was decidedly immature, paving the way for the much-improved Australian Cruiser Tank Mk. III "Thunderbolt".