Tokyo Charter and Legality Principle 435
XI JEAIL 2 (2018)
The legacies of Tokyo Trial have been overlooked and questioned partly because
prosecuting aggression was allegedly a violation of the principle of legality. This essay
argues that the trial should not be overlooked for this reason because the legality debate
at the trial provides insights into the interplay between the principle of legality and
sources of international criminal law. Besides the majority judgment, some minority
opinions could shed light on the nature of the Tokyo Charter by distinguishing between
jurisdiction and applicable law and link the issue to the legality challenge. Although
the Tokyo Charter was formally different from the Nuremberg Charter, both of them
are substantive in nature so that the tribunals were allowed not to address the legality
challenge. In addition, prosecuting aggression was arguably not a violation of the
principle of legality because this principle, at that time, did not bind ex post facto
legislation against international crimes committed during World War II.
International Military Tribunal, IMT, IMTFE, Tokyo Charter, ICC.
Substantive or Jurisdictional?
The Tokyo Charter and the
Legality Challenge at the
Tribunal for the Far East
∗ This paper is a summarized and updated version of the author's LL.M. thesis submitted to the graduate committee of
the University College London in 2017.
∗∗ MPhil Candidate (Oxon); Part-time Researcher at the Center for Tokyo Trial Studies of Shanghai Jiao Tong University.
Msc. (VU Amsterdam), LL.M. (UCL), LL.B. (Shanghai Jiao Tong Uni.). ORCID: https://orcid.org/0000-0003-2973-
7922. The author may be contacted at: firstname.lastname@example.org/Address: Brasenose College Radcliffe Square Oxford
OX1 4AJ UK.