Complex sentence: In September 1942, the IJN defeated by in the Battle of Midway drew up a new armaments expansion plan combined by the 5th Naval Armaments Supplement Programme and the 6th Naval Armaments Supplement Programme to build the aircraft carrier rapidly.
Split into simpler sentences: In September 1942, the IJN defeated by in the Battle of Midway drew up a new armaments expansion plan. This plan was combined by the 5th Naval Armaments Supplement Programme and the 6th Naval Armaments Supplement Programme to build the aircraft carrier rapidly.