Under the U.S.-Japan Security Alliance, Japanese governments have allowed US bases on Okinawa in exchange for a US commitment to defend Japan from external attacks. 75% of US military forces are stationed in Okinawa, despite Okinawa only constituting to 0.6% of Japan's total landmass. Throughout the history of the presence of US military presence in Okinawa, multiple mass protests have taken place. Yet, new military bases continued to be built.