Would japan have surrendered without the a-bomb devastations in WW2?

Yes, they would have eventually surrendered without the use of an atomic bomb. The last island invasion of WWII occurred on Okinawa, an island the U.S. planned to use as an aerial outpost for the Japanese mainland. Realistically, after the defeat of the Japanese Navy at the Battle of Midway, the Imperial Japanese were unable to rebuild a successful, effective navy. This enabled the allies to eventually close every port on the main island of Japan. Once their colonial imports stopped reaching the factories on the mainland, Japanese war production drastically spiraled downward. Every resource was being poured to the war efforts, civilians were starving, health care plummeted... The Japanese would not have been able to carry on a war much longer even without the atomic bombs. With the closing of Japanese ports, the lack of natural resources, and a new technique perfected by the british, the allies would have forced a surrender anyway. The British introduced a technique of dropping a concussion bomb which sucked the air out of the blast radius, immediately followed by an incendiary bomb. The rush of air returning to the low pressured air fueled the incendiary explosion. The U.S. systematically fire-bombed every major Japanese military installation, then turned to centers of war production. There was NO JAPANESE ECONOMY. Several high ranking Japanese military officers had already staged an unsuccessful coup to overthrow the emperor. The war was over, it was a matter of time. An invasion on mainland was not necessary even without the a-bomb.