What could the World War II US military do with today's conventional stockpile and the training to maintain it?
Short answerIt could cripple Germany and Japan within weeks, with most delay coming from moving modern forces into position rather than defeating resistance.
NotesTomahawk missiles could strike Japanese bases from ranges the period's interceptors and defenses could not meaningfully contest. Modern sensors and precision weapons would dismantle the operational system around those bases rather than merely damage individual targets. Even excluding nuclear weapons, conventional supercarriers such as the Kitty Hawk class would bring overwhelming aviation capacity once moved into theater. Germany would face the same mismatch in range, accuracy, and logistics. The principal delay would be moving the modern arsenal into position, not overcoming 1940s defenses.