By the winter of 1917-18, Germany was starving and its economy was in shambles. The Spring Offensive of 1918 pushed the Allies back 50 or 60 miles but cost the Germans over a million men that conscription could never make up. They'd given it their last best shot and failed, while the Americans were landing 10,000 men a day, and Canada likewise was untouched at home and shipping over healthy young conscripts in large numbers. meantime there were ever more Communist and Socialist agitators in the streets of Germany encouraged by the fall of the Tsars and calling for the overthrow of their absolute monarch. Unlike Hitler Wilhelm had somewhere to go.
When the Kaiser fled to Holland, Germany was indeed defeated and humiliated. The vengeful seizure of the Saar and Rhineland and the ruinous reparations ensured that the wounds would stay unhealed, until someone came on the scene to exploit them. The real question isn't how to win wars, but how not to make the losers into worse enemies.
