What was the Japanese response to this Allied declaration?

Failure to comply would mean “the inevitable and complete destruction of the Japanese armed forces and just as inevitable the utter devastation of the Japanese homeland.”

Explanation:

In exact words

Ten days later, the Allies issued the Potsdam Declaration, demanding the “unconditional surrender of all the Japanese armed forces.” Failure to comply would mean “the inevitable and complete destruction of the Japanese armed forces and just as inevitable the utter devastation of the Japanese homeland.

they thoght they were going to nuke each other