Even then, it was to stave off a massive invasion estimated to cost something like 2-5 million US soldier's lives, and some almost 60% of the Japanese population was also expected to fight to death, and around 80-90% of the country (Japan) was already starving/getting less than the recommended caloric intake, so its estimated another large chunk of the ~40-50% of the population who didn't die fighting would have also starved to death.
Massive country wide burst damage (so to speak) is preferable to a slow, brutal, meat grinder of a siege across multiple islands and atolls against a dug in and fanatical opponents who will fight and starve to death rather than relinquish ground.
Not at all comparable to League imho though.
If you actually want to compare to armed conflicts, there is a funny trend through out the ages, you wanna know what it is? Defense actually outscales offense, all the way up until you get to those aforementioned nukes, and literally destroy the world instead killing both. Take steel plate armor. Swing a sword at it, hell, break 500 hundred of your best steel longswords against that plate. You won't cut it, you won't chip it, you won't even bend it. You sure as shit wont pierce or break it, and even if you stab it halfswording, and drive the point in as hard and deep as you can, you still wouldn't get it in far enough to get across past the cavity to actually hit the gambeson of whomever would be wearing it. Next, try shooting as many arrows as you want from as close as you want. Try to get just one into that armor. Try to get one stuck into it. Try to get one to actually pierce. Try for hours, or years. Unless its already broken some other way, you simply won't be able to. Unless you have a mounted knight charge a lance through that, the plate will fucking hold, and weapons will splinter and break against it. Why do you think people would pay the modern equivalent of 5-10 million dollars for a single set of proper plate armor? That shit made you all but immune to most forms of weapons, and most ways of getting killed, even during sieges and repeated pitched battles. It was vastly more common for knights to be captured, enslaved, tortured, or ransomed then it ever was for them to fall in battle. That's what the paiges, squires, and yeoman without proper armor did. A knight in armor, even unmounted was considered the equal to 10 of his fellows just from the armor he carried, and how invulnerable they effectively were unless against morning stars and charging cavalry. Defense provides stability, it allows and necessitates strategy and tactics to overcome it, or find weakness in it, instead of simply bashing each other over the head with a club and brute forcing literally everything without a thought to how. Offense, on the other hand, is pure, raw brutality, and it is a race to the bottom, mutually assured destruction, and literally realizing the game/battle/war is not worth fighting for any single person involved. Its simply not worth playing period, as its tantamount to suicide.
You ever see the movie "WarGames?" If RIOT keeps this bullshit asshatery, we really will be in a world where "the only winning solution, is not to play."