Complex sentence: The Allies, expecting to encounter Japanese Bf 109s in combat, assigned a code name of "Mike" to the Messerschmitts, in the event one were flown in combat by the Japanese.
Split into simpler sentences: The Allies, expecting to encounter Japanese Bf 109s in combat, assigned a code name of "Mike" to the Messerschmitts. In the event one were flown in combat by the Japanese.