Yes, a common view at the time was that the only de-escalation possible would have been through workers cooperation, which is why so much of the Marxist flank of the SFIO argued in favour of pacifism: to buy time for the workers to unite.

Which probably wouldn't have worked, but maybe it could have been a much, much smaller conflict.

Understanding the lesson of the Guns of August was a big part of the anti-MAD/nuclear disarmament movement during the cold war: if you build a doomsday weapon eventually you will use it. A country does not spend as much effort and money as the European powers spent preparing for war without eventually going to war.