Answer :
B-29's was the new technology that allowed the Allies to bomb the Japanese mainland more effectively.
After the Japanese attack on Pearl Harbor. The United States when to full war with Japan. The US wanted to punish Japan by bombarding the main Japanese cities, and destroying factories contributing to the Japanese´s war effort. As a consequence of this, there was a high number of Japanese civilian casualties.
The plans to attack Japan have been drawn before the pacific war but, it was not possible to execute until the new B-29 Superfortress were ready to action. These new super planes were more technologically advanced than their predecessors and much better able to reach the main land in Japan.
Now America and the Allies could increase the air campaign in Japan´s main land thus, bringing the war to a quick end. The B-29 Superfortress were also used to lunch the Atomic bomb over the cities of Nagasaki and Hiroshima, bringing the war in the pacific to an abrupt end with the Japanese unconditional surrender.
