First, I think you should read some WWII history about Japan and the mindset of both the general population and military. After reading the predictions about what the expected results would be if the US had to do and amphibious landing were you might change your mind about how the war was stopped. As @OverTheTop posted the casualties on both sides would have been astronomical and every city in Japan would have been flattened. General Curtis LeMay had already ordered the fire bombing of Tokyo and other cities. Japanese houses were paper and wood. The fire storms were so intense people would burst into flames. If something like that happened now it would be a war crime. Stopping the war with atom bombs was probably the best way to save the lives of the Japanese.it wasn’t ok, and Israel should learn from our mistakes. This applies to Using large scale military to combat terror as well, it really just makes it worse.
Second, The number of soldiers, the quantity and types of weapons and their sophistication makes Hamas an army in my book. Just about the only thing Hamas doesn't have are tanks. They are inflecting a lot of casualties on Israel. If Hamas wasn't a capable army this conflict wouldn't have happened.