Answer:
The victor countries should try to help the defeated nations economically, instead of imposing very harsh reparations measures.
More specifically in the case of Germany, instead of making Germany pay enormous amounts of money in reparations, the victorious nations should try to help Germany economically, in order to rebuild the country, strenghten its democracy, and avoid the rise of power to populist dictators like Adolf Hitler.
The victorious nations should also try to work together with the Soviet Union, despite the ideological differences, for example, by setting up trade agreements.
All this actions would be focused on improving the stability of the world, lowering tensions, and improving the living standards of people, with the goal of keeping peace and avoiding a new war.