One of the fascinating things an old fool can do until that day is to use Google Maps to study places around the world. One can even infer why there might have been a concentration of naval force at Pearl Harbor in Dec., 1941. There were not then satellites and sensors and submersibles we track our oceans with these days. 
There simply isn't anything anywhere in that part of the ocean. Ocean travel, even today, is measured in days at sea, Hawaii just shy of a week from everywhere "close".
On every island in the Pacific you'll find an airfield built in WWII. 5,000 ft. for most because no jets then, which is also to say less weight. 7,000 ft. for those which handle jets, but the island also needs to handle the weight of a jetliner as well.
But the biggest component of why we use big bombs is because the outcomes are not clear. In retrospect nearly everything can be wrong, even foolish. Such is history, and books. It's a different issue entirely to look forward at what we should do next.