To help you answer that might I suggest reading the opening statement made by Robert Jackson, then on leave from his position as an Associate Justice of the Supreme Court to serve as Lead US Counsel (chief prosecutor) at Nuremberg.
Let me offer the following from that statement:
The American dream of a peace-and-plenty economy, as well as the hopes of other nations, can never be fulfilled if those nations are involved in a war every generation so vast and devastating as to crush the generation that fights and burden the generation that follows. But experience has shown that wars are no longer local. All modern wars become world wars eventually. And none of the big nations at least can stay out. If we cannot stay out of wars, our only hope is to prevent wars.Please note the portion I have bolded.
I am too well aware of the weaknesses of juridical action alone to contend that in itself your decision under this Charter can prevent future wars. Judicial action always comes after the event. Wars are started only on the theory and in the confidence that they can be won. Personal punishment, to be suffered only in the event the war is lost, will probably not be a sufficient deterrent to prevent a war where the warmakers feel the chances of defeat to be negligible.
But the ultimate step in avoiding periodic wars, which are inevitable in a system of international lawlessness, is to make statesmen responsible to law. And let me make clear that while this law is first applied against German aggressors, the law includes, and if it is to serve a useful purpose it must condemn aggression by any other nations, including those which sit here now in judgment. We are able to do away with domestic tyranny and violence and aggression by those in power against the rights of their own people only when we make all men answerable to the law. This trial represents mankind's desperate effort to apply the discipline of the law to statesmen who have used their powers of state to attack the foundations of the world's peace and to commit aggressions against the rights of their neighbors.
You can read the entire statement here