THE US INVADED OKINAWA TO BUILD A MILITARY BASE THAT IS CLOSE TO JAPAN FOR AN EASIER INVASION THAT BENEFITED AIR AND LAND FORCES; THE US INVADED OKINAWA TO BUILD A MILITARY BASE AND PREPARE FOR A LAND AND AIR INVASION OF JAPAN; THE US INVADED OKINAWA TO SET UP A BASE NEAR JAPAN FOR A BETTER INVASION; THE US INVADED OKINAWA FOR WAR STUFF