Thanks, Monique, for the helpful link to official French resources, which can hardly be suspected to spread lies to denigrate the allied war plans (... even if the current president is a "socialist").

To those who cannot read French, I recommend entering the paragraph starting with "Du 6 au 8 septembre 1906" to Google-Translate. The full scenario already planned in 1906, secretly, but with enthusiasm both from British and French generals.

The general public was not quite as well-informed, but could guess a lot - so did the German leaders. All leaders did what they had planned for years in advance - whether or not they welcomed it.