I think there was another small event that occurred around the same time that confounds things a bit. An event which VERY heavily involved industrialists.

No, it wasn't just war profiteering: many countries which were on the wrong side of that equation also saw an unprecedented elevation of the middle class. That is the opposite of what you would expect in a war profiteering story, but it's exactly what you would expect in a labor bargaining power story.

Funnily enough, there is a compelling argument that France adopting the 40 hour work week weakened its army and that is what encouraged Hitler to become aggressive. That small event might never have occurred without the 40 hour work week.

Mmmhmm. Every little labor victory helps Hitler, dontcha know? You wouldn't want to help Hitler, would ya?

These arguments were omnipresent at the time but they suddenly faded away when Hitler got his ass kicked. I wonder why?

You might want to revisit the history books. WWII didn't help Hitler.

My point exactly: why do you think the anti-labor arguments that rhyme with yours went away when Hitler got his ass kicked?

It didn't go away...? We wouldn't be able to have this discussion if it did.

I have no idea what you are trying to get at. If it is that wars can be won by working 40 hours per week, that is highly unlikely to be true. The 40 hour work weeks went by the wayside during the war. The US, for example, mandated a minimum of 48 hour workweeks in manufacturing during the war.