The terms of the peace between France and Germany is going to be crucial here. If France doesn't get reparations for the damages Germany has done and Alsace-Lorraine, which were the minimum for most French people (85% polled in 1917), there will be a civil war and a series of assassinations. France would be incredibly unstable. Of course there would be a need to hold together, but a peace without the above will be a viewed as a major loss and it would leave France crippled. Beyond that the 3rd republic is going to collapse as a result of all this. Socialists and pacifists are going to be proven right, which will result in a major social schism that will be incredibly difficult to overcome. Expect a communist revolution on par with the Paris commune, as well as military intervention with bloody results further creating difficulties in the coming years.
Germany is not going to be much better off. The Kaiser is going to be discredited and probably will have to step down at some point, though his heir, the Crown Prince, is not very well liked either. Ludendorff and Hindenburg are going to be heroes and probably the saviors of the monarchy, but this will have a nasty effect on German post war military theory. Beyond that, there will still be the elements of the Socialist revolt, which will be felt in the very next election. However, this will mean that the military and ultraconservatives are going to throwing at fit, which could very well mean that the Reichstag is suspended. This in turn means a civil war in Germany, one that has the potential to get very nasty, especially as the army and navy have their own fault lines based on class. While working out their internal problems, it will prevent any further aggression, which will have important effects for the future of the Habsburgs. I still see them falling apart and getting partly absorbed into Germany with the rest set up as protectorates under German influence.