The Charter makes the planning or waging of a war of
aggression or a war in violation of international treaties a crime;
and it is therefore not strictly necessary to consider whether and to
what extent aggressive war was a crime before the execution of the
London Agreement. But in view of the great importance of the
questions of law involved, the Tribunal has heard full argument from
the Prosecution and the Defense, and will express its view on the
matter.
It was urged on behalf of the defendants that a fundamental
principle of all law-international and domestic-is that there can be
no punishment of crime without a pre-existing law. "Nullum
crimen sine lege, nulla poena sine lege." It was submitted
that ex post facto punishment is abhorrent to the law of all
civilized nations, that no sovereign power had made aggressive war a
crime at the time that the alleged criminal acts were committed, that
no statute had defined aggressive war, that no penalty had been fixed
for its commission. and no court had been created to try and punish
offenders.
In the first place, it is to be observed that the maxim nullum
crimen sine lege is not a limitation of sovereignty, but is in
general a principle of justice. To assert that it is unjust to punish
those who in defiance of treaties and assurances have attacked
neighboring states without warning is obviously untrue, for in such
circumstances the attacker must know that he is doing wrong, and so
far from it being unjust to punish him, it would be unjust if his
wrong were allowed to go unpunished. Occupying the positions they did
in the Government of Germany, the defendants, or at least some of
them must have known of the treaties signed by Germany, outlawing
recourse to war for the settlement of international disputes; they
must have known that they were acting in defiance of all
international law when in complete deliberation they carried out
their designs of invasion and aggression. On this view of the case
alone, it would appear that the maxim has no application to the
present facts.
This view is strongly reinforced by a consideration of the state
of international law in 1939. so far as aggressive war is concerned.
The General Treaty for the Renunciation of War of 27 August 1928,
more generally known as the Pact of Paris or the Kellogg-Briand Pact,
was binding on 63 nations. including Germany, Italy, and Japan at the
outbreak of war in 1939. In the preamble, the signatories declared
that they were:
"Deeply sensible of their solemn
duty to promote the welfare of mankind; persuaded that the time has
come when a frank renunciation of war as an instrument of national
policy should be made to the end that the peaceful and friendly
relations now existing between their peoples should be perpetuated .
. . .