Complex sentence: The Manshukoku Hombu (Manchurian Air Force) was the national Manchurian air force in WWII.in theory such unit debt to protect at country and provided cover to land forces; theirs was figthing aligned to Axis Powers alliance.
Split into simpler sentences: The Manshukoku Hombu (Manchurian Air Force) was the national Manchurian air force in WWII. In theory the unit was supposed to protect the country and provided cover to land forces; they were aligned with the Axis Powers alliance.