You have "less war" when one side dominates and the other surrenders quickly. Two evenly-matched sides can continue fighting for decades.
That worked with Poland in 1939 until Hitler decided to continue and attack the rest of Europe.
Look, I'm not trying to discuss strategy or glory or good vs evil, just the concept of "less war." WWII was 6 years. US involvement in more recent conflicts like Afghanistan, Vietnam, Iraq was a lot longer. Meanwhile various civil and border wars have gone on beyond a decade.