Using Force Lawfully in the 21st Century

• Author: David B. Rivkin, Jr. - Lee A. Casey
• Position: Partners in the Washington, D.C. office of Baker & Hostetler, LLP
• Pages: 319-336

XIV

Using Force Lawfully in the 21st Century

David B. Rivkin, Jr. and Lee A. Casey*

Introduction

Waris not alaw-free zone. There have always been rules governing when a

State can legitimately use armed force. In one familiar ancient example,

in the 12th century BC the Mycenaean Greeks most likely sacked the city of Troy

because it was rich and vulnerable. As summer 2004 moviegoers saw, however, by

800 BC the poet Homer felt compelled to clean up the story with ajustificatory act

of Trojan perfidy—the kidnapping of aSpartan queen by aTrojan prince. Accord-

ingly, amore respectable casus belli, rooted in revenge, love and passion, was pro-

vided in The Iliad1for what otherwise would have been blatant Greek aggression.

Thus, even in the Age of Heroes, when armed combat was glorified and gods were

believed to fight side-by- side with men, unalloyed aggression was viewed as mor-

ally questionable. The perceived need for some legal justification for unleashing

the dogs of war has remained aconstant ever since.

At the beginning of the 17th century, Hugo Grotius noted that, although "[t]he

grounds ofwar are as numerous as those of suits at law Three justifiable causes

for war are generally cited: defense, recovery of property, and punishment."2There

is little doubt that the casus belli regularly invoked by States over the subsequent

350 years fell into one or more of these categories. To be sure, given the broad na-

ture of such concepts as "defense" or "punishment," the potential for their abuse

or bad faith application has been quite obvious. Only ahopelessly unimaginative

*Messrs. Rivkin and Casey are partners in the Washington, D.C. office of Baker &Hostetler,

LLP.

Using Force Lawfully in the 21st Century

statesman would have been unable to articulate some plausible sounding basis for

his belligerent aims, whatever they might be.

Not surprisingly, while some leaders took full advantage of the considerable

elasticity inherent in the traditional resort-to-force legal and ethical strictures,

dubbed jus ad bellum, others have sought to leash the dogs of war by devising ever

more rigid and proscriptive rules. Indeed, the efforts to ban armed conflict alto-

gether (of which the 1928 Kellogg-Briand Pact3is perhaps the best-known exam-

ple), or at least substantially constrain the use of violence, are as old as, or in some

instances, even older, than war itself. The search for legal limitations has intensified

in the 20th century, as the carnage of mechanized warfare and the horrendous ca-

sualties suffered during the two World Wars have substantially diminished com-

bat's erstwhile heroic luster.

These regulatory efforts featured most prominently ano-first use concept,

whereby force could be used only in response to an attack, rather than as an in-

strument of aggression. However, given the fact that waiting to absorb an attack by

an enemy before responding can be arisky strategy, most statesmen and generals

have sought to protect the option of using force first, albeit in anticipation of the

enemy's attack. This anticipatory self-defense doctrine has been ahardy perennial

in international law.4

Anticipatory Defense's Historical Record

Burning the Caroline

The 1837 Caroline incident,5involving the British destruction of an American ship

in US territorial waters, buttressed the modern international law doctrine of "an-

ticipatory self-defense." In accepting the British explanation that the Caroline was

destroyed in "self-defense," anticipating that she would again be used to assist the

Canadian insurgents, American Secretary of State Daniel Webster acknowledged

in 1841 the doctrine's validity, although he attempted to limit its application to the

most extreme circumstances—where the need is "instant, overwhelming, and leav-

ing no choice of means and no moment for deliberation"6—leading many subse-

quent commentators to conclude that the doctrine could be invoked only when the

threat was imminent.7

Of course, robust anticipatory self-defense had been awell-accepted rule,

firmly grounded in all-important State practice, for centuries before the Caroline

went crashing over Niagara Falls. Indeed, Webster's rather restrictive wording of

this rule was driven largely by the US desire to limit the circumstances in which

Britain or any other European power could claim alegitimate basis for using

force on American soil. In a sense, the Caroline doctrine was meant to provide

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