What would happen if WW2 happened today?
I'd be even more confused than I am already. I'd have imagined all that stuff about what grandad did in the war. All the bombing raids, Hitler, the tanks & the Spitfire planes. All the repeats of "The Great Escape" I'd watched every Christmas would have been based on a lie. Vera Lynn & "The White Cliffs Of Dover" would have been a tune I'd thought up myself. Nobody would have won anything yet, & those WW2 bunkers I went into in Jersey would not have been real, (though they felt pretty solid to me at the time). No, I'd have imagined it all & be needing to build my Anderson shelter shortly.
All these questions on Quora by people worried about N.Korea starting WW3 would be being asked far too soon. The tub of lard would have to be patient & wait until we'd had WW2 first. That's a point, would we have nukes in WW2? They wouldn't have been invented yet, but Kim's already got 'em. I've seen it on the telly. No need to worry then, Kim will sort that Hitler out. "Come on you dotard with the funny moustache, call me "shorty" & I'll nuke you".
That's it then. WW2 would be over in a flash & N.Korea would rule the world. At least there'd be no need for WW3 . Hope they don't force me to have a funny haircut like our "Dear Leader," who will do wonderful things here & be greatly respected by everyone at "The Rising - Un" pub & all of us in the U.K. (United Korea).
With seventy years of experience with nuclear physics, but without the gut turning experiences of the closing days of the Pacific War-and with most of the world's industrial powers are unprepared to fight a ground war as Hungary and Belgium, say, were in 1938, regional nuclear war would be all but inevitable. This would lead to the collapse of Europe and urgent expeditionary desired amoung its barely surviving nations-and global nuclear war.
Europe, Northern Europe, North America would be pounded into radioactive wasteland. Most lands south of the equater would have some human society left, but they would have high cancer and spontanoues miscarrage rates and would have to adapt to several decades of "Nuclear Autumn" cooler years with little sunlight because of dust in the upper atmosphere.
I am going to paraphrase Eienstein " I do not know what weapons the Third World War will be fought with, but the Fourth will be fought with sticks and stones."
I assume you mean a war -like- WW2. It could not happen today. A sneak attack of any great military magnitude is virtually impossible. We have satellites watching for any sizable movement of troops and material A stealth nuclear attack could happen, but if not accompanied by extensive military operations it would not be a war like WW2.