The Germany "victories" against Imperial Russia in 1917 and France in 1940 both left Germany in a far worse off position. Really they are examples of triumphs that were failures in disguise.
I have to strongly disagree with this statement here. Had the Wallies been able to bog down the Germans in France during WWII, then the Germans would have been infinitely worse off. Yes their position was still untenable in the long run but it's crazy to think that it hurt them more than helped them.
I would say the same for Russia's' collapse in WWI, even though it was still a massive burden for the Germans to occupy, that situation is still much better than an active front sucking in munitions and men.
Also, I understand that the Germans would have been better off still, had they not gone to war in the first place.
Edit: instead of say Germany would have been better off if France lost quickly, I should have said hitler would be better off.. It does make sense in a way, that had the Germans failed to knock out France quickly, the war would have likely ended much sooner than in OTL.
But then again, I think France falling puts Germany in a better negotiating position if they were serious about making peace, but we all know that was never gonna happen with hitler in charge, with his plans for the East..