Shadows across the Path 469seen as a substitute for such trials, implemented at the national, rather than
the international, level.
Universal jurisdiction has deep historical roots. Th e core idea was articu-
lated by Cicero in the fi rst century b.c., when he spoke of a pirate as “a com-
mon foe” of the world at large. An immediate implication was that there is
no obligation to adhere to agreements with such rogues (ransom agree-
ments, for example, need not be honored). But another consequence could
be that anyone (or at least any established government) is allowed to take
action against pirates on the high seas. In Cicero’s own time, the famous
general Pompey did precisely that, mounting a successful military expedi-
tion against a pirate community based in Cilicia (in present- day southern
Turkey) in 67– 66 bc.
In the sixteenth century, Gentili pronounced pirates to be “common en-
emies” of humanity in general. As “scorners of the law of nations,” he main-
tained, “[t]hey ought to be crushed by all men.” From these sentiments,
there grew to be a general ac cep tance that persons accused of piracy could
be prosecuted in the courts of any state, regardless of the nationality of ei-
ther the alleged pirates or their victims. Vattel was one of the earliest to hold
explicitly that criminal proceedings in national courts could be brought
against these scoundrels.
No signifi cant expansion in universal jurisdiction occurred until aft er
World War II, when the idea was incorporated into the Geneva Conventions
of 1949. In cases of suspected “grave breaches” of specifi ed rules, states parties
to the conventions are actually required to institute prosecutions— if neces-
sary, invoking universal jurisdiction in order to do so. Th is marked the fi rst
occasion in history in which exercise of universal jurisdiction became man-
datory instead of merely optional.
On the whole, universal jurisdiction was long regarded as being of only
marginal importance in practice, since it applied to so small a number of
off enses— only piracy and grave war crimes. Over the years, though, the list
began to grow, with concern over terrorist acts providing an important im-
petus. A major fi rst step was a convention against aerial hijacking con-
cluded in 1970. Th is eff ectively authorized states to deploy universal juris-
diction against suspected hijackers. A number of similar authorizations
followed in terrorism- related areas, such as placing bombs on airplanes, hos-
tage taking, maritime terrorism, and terrorist bombings.