Today is the anniversary of V-J Day, also know as Victory in Japan Day. Originally this was celebrated as a national holiday in many places in the US but fell out of favor as a holiday as it was thought to be offensive to Japan who is now an ally.
There were many factors that caused Japan to surrender - Hiroshima and Nagasaki were certainly a large part of it. After three years of brutal war in the Pacific, negotiations with Russia, and people in Japan petitioning their government for peace, it seemed inevitable that Japan would not win the war. If you are not familiar with the history of the war with Japan, here are some good books to check out.
Hiroshima by John Hersey - Hiroshima tells the story of six survivors of the bombing of Hiroshima. Hersey, a war journalist, originally wrote this as an article which was published in the New Yorker magazine in 1946. It was put into a book by the Alfred A. Knopf publishers and has never been out of print since that time.
Duty: A Father, His Son, and the Man Who Won the War by Bob Greene - Another non-fiction book, Bob Greene went back to his hometown in Ohio to be with his dying father, a taciturn man who kept referring to a local citizen as the "man who won the war." He was Paul Tibbets, the pilot of the Enola Gay, the plane that dropped the atomic bomb on Hiroshima. Greene went on to develop a friendship with Tibbets and learned many things about the war and the men who fought it that his father never shared.
A Pledge of Silence by Flora J. Solomon - This novel tells the story of an Army nurse stationed in the Philippines and taken captive, along with the non-native population, when the Japanese invaded the Philippines.
Along the Broken Bay by Flora J. Solomon - In her second novel Solomon's heroine is an American expat living in Manila. When the Japanese invade the Philippines, Gina Thorpe flees with her daughter to the mountains where she joins the resistance. Gina goes back to Manila to open a nightclub for the Japanese invaders and to spy for the resistance.
Killing the Rising Sun: How America Vanquished World War II Japan by Bill O'Reilly and Martin Dugard - This non-fiction book is a terrific primer on the war in the Pacific. It reads like fiction and is not as long as some of the more detailed books.