Was there any evidence at the time suggesting that Imperial Japan was ready to capitualte to the Allies without the use of such weapons? If so, what other credit is due for victory in Japan? Just curious about the subject after some light reading this weekend. Thanks in advance for all responses, your time and knowledge is greatly appreciated!
This question gets asked here pretty frequently; this section of our FAQ may be of some interest to you. The tl;dr is: What was primarily responsible for the Japanese capitulation is one of those questions where reasonable people can look at the same evidence and draw different conclusions; particularly in recent years with the opening of (formerly) Soviet archives, we have better knowledge of how the Soviet declaration of war on Japan affected leadership decisions.
These threads in particular may be of interest: