The war would have dragged on much longer and it would have been bloody beyond imagination. Once we developed the atomic bomb Berlin would have went up as radioactive ashes and dust. Repeat as necessary.
I don't have time to do the research but there is very good reason to believe that the USA would not have dropped the atom bomb on a European city. Call it a racist motive if you will.
As for "repeat as necessary," the USA postured that they could have bombed every Japanese city to rubble but the fact is we did not have enough fissile material for a fourth bomb. Extracting U-238 was still a slow and imperfect process; ditto with Pu-239. If I recall correctly the absolute dearth of fissile material in 1945 was a classified secret for many years.
The fact that we were still, seriously, preparing for the invasion of the island of Honshu is proof positive that Truman and the Department of War did not think that two atom bombs would not be enough to deter the Japanese.