The unconditional invitation

What is the difference between something being conditional versus unconditional? How much can such a difference actually affect our lives? One example from modern history is WWII Japan. While the ferocity of Japanese soldiers had been seen from the outset, this became markedly more so as American forces reached homeland soil; specifically Okinawa and Iwo Jima. The bloodiness of battles there were such that even today terms kamikaze, seppuku, and banzai are familiar. Yet it can be argued that it was this very same fantacism that, in part, shaped the world changing events in Hiroshima and Nagasa...