I think one big difference between now and the last world war is that it's basically impossible to hide oceangoing convoys of weapons and troops. Even if the USA reequips for a war economy, they have no way of delivering aid to their European allies reliably in a hypothetical non-nuclear WW3.
Edit: Until everyone decides to go Kessler Syndrome and take out enemy satellites.
Submarines are also absurdly more capable than they were in WWII, able to launch missiles from, I think, underwater and guide them to surface ships far away.
And the Ruskies supposedly have that unlimited range nuclear torpedo.
I think one big difference between now and the last world war is that it's basically impossible to hide oceangoing convoys of weapons and troops. Even if the USA reequips for a war economy, they have no way of delivering aid to their European allies reliably in a hypothetical non-nuclear WW3.
Edit: Until everyone decides to go Kessler Syndrome and take out enemy satellites.
Submarines are also absurdly more capable than they were in WWII, able to launch missiles from, I think, underwater and guide them to surface ships far away.
And the Ruskies supposedly have that unlimited range nuclear torpedo.