"The longer we wait before taking any kind of action, the weaker his people will be and the greater threat he will present to the rest of the world." - That somehow doesnt make sense to me. Am I missing something?
"You don't want someone who is crazy (and quite likely paranoid too) having the ability to use nuclear weapons." - He may be paranoid(idk), but you are saying to strike first because you are afraid of what they may do...
"Don't get me wrong. War is not a good thing. People will die, it will be messy, but this is the reason we have armies. Those people sign up voluntarily to risk their lives and protect others." - If USA attacks the ones to suffer will be the Koreans mostly, and the soldiers. War is never just messy(That's the understatement of the year). The reason we have armies... Right if you have a gun you have to use it right? Btw the pic with the nuclear explosion where you say "Do we wait for this to happen again?", are you referring to Hiroshima and Nagasaki? If you are then I dont know what to say.
From what I read your reasons are basically fear. Actions driven by fear, rarely get the best results.
Sometimes fear is warranted. These are the exact kind of arguments that were made during the run up to World War II.
Maybe Kim Jong-un is also afraid that the west is interfering in his own little world and that's why he's making nuclear weapons.
OK I understand what you are saying. It is possible.