CRANFIELD UNIVERSITY DAREN BOWYER JUST WAR DOCTRINE

As with religious formulations of the doctrine, Grotius’ legal approach considers not
just recourse to war but also its conduct. Book 3 of De Jure is largely given over to
issues of jus in bello, conforming to the twin pillars of proportionality and
discrimination. It should also be noted that Grotius’ work is a treatise on the ‘Law of
War and Peace’ and he places considerable emphasis on establishing appropriate
mechanisms for the peaceful resolution of disputes, including conferences, arbitration
and even decision by lot! So, just as Aquinas rests the justification of resort to war on
the absence of a higher authority who can enforce a just peaceful resolution, so Grotius
acknowledges that any curtailment of a state’s right to wage war, rests upon the
existence of a mechanism that will render viable peaceful alternatives. He also follows
Aquinas in noting that just cause alone is insufficient; the belligerent must also have
righteous intentions: it is not acceptable to take advantage of the existence of a just
cause simply to further ones own ends. We are also reminded that a just war can
become unjust if it gives rise to unjust acts. (This is an issue to be examined further
when considering how unjust conduct can undermine the grounds on which a war was
embarked upon; jus ad bellum is not a simple hurdle that once crossed can be forgotten
for the duration of the conflict; the grounds upon which a war is justified may have
consequences for the manner in which it is prosecuted.)
Pufendorf (1632-94) followed Grotius’ understanding of natural law and built upon its
foundations an extensive codification of international law. Like Grotius he draws
parallels between the domestic and international context and in his consideration of how
war can be incorporated within the proper constraints of law, he too draws extensively
on the just war tradition. It is a matter of natural law that men (and by extension states)
should strive to live in peace with one another but war may sometimes be permissible
or, indeed, necessary when there is no other way to defend what is ours or to vindicate
our rights. ‘In this situation, however, good sense and humanity counsel us not to resort
to arms when more evil than good is likely to overtake us and ours by the prosecution of
our wrongs.’ 151 Just cause is either defensive: essentially self-defence; or offensive: for
the enforced extraction of reparation for wrongs done. But Pufendorf is firm about
using force only as a last resort and warns of both openly unjust causes and those that
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