During his clerkships, Tanner assisted judges by conducting research and drafting memoranda on challenging, emerging, and
unsettled points of law.
It is, at least, apparent that the debates about humanitarian intervention by military force in the last decade, about the creation
of international criminal tribunals in a number
of cases, about the idea
of a state's «universal jurisdiction» in cases
of violations
of the Genocide Convention or other «crimes against humanity,» about how far the global war on terror may proceed without violating the rights
of states, and most recently, about the United - States - led use
of force against the Saddam Hussein regime in Iraq, have all raised important
points of positive and customary international
law, and that in every one
of these cases the outcome remains
unsettled.