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Terrorists and other adversaries will not observe the laws of war, but highly refined concepts of what constitutes a lawful target are deeply ingrained in the American military. At right, a USAF pilot scours the horizon. |
When bombs fall, controversy about the law of war is seldom far behind. Airpower
is a weapon of such reach and potential devastation that it has long provoked
sharp debate about the legality of its operations. In recent campaigns, where
combatant casualties have been extremely low, accidental civilian deaths from
collateral damage have made headlines. However, senior air planners show great
concern for upholding the law of war, in no small part out of a desire for domestic
acceptance and to maintain the international unity of effort.
Even in this age of precision warfare, many still raise questions about what
constitutes a “lawful target.”
When a command’s staff lawyers advise a combatant commander, they are
drawing on centuries of tradition as well as international conventions and treaties.
Deciding whether a convoy of vehicles in a Predator Unmanned Aerial Vehicle’s
scope is a lawful target demands working knowledge of the principles of armed
conflict and a hefty dose of the commander’s judgment.
The Origins of Just War
There are no lawful targets without “lawful” wars. The first concepts
of lawful conduct in war sought to make war an instrument of national policy
rather than just an exercise in barbarity. Limiting the right to make war was
the first step. Among the Romans, Cicero wrote of just war. St. Augustine and
St. Thomas Aquinas both regarded war as one of the divine rights of kings. These
two Christian philosophers formed the first core of just war doctrine among
European societies. Their concepts of just war covered two areas: waging a war
for justifiable reasons and conducting war according to a set of rules that
recognize mercy and proportionality.
To Augustine, it made “a great difference by which causes and under which
authorities men undertake the wars that must be waged.” He defined war
as part of the natural life of the state, as long as the war aimed at ultimately
securing peace. A monarch had a right to wage war, said Augustine, but had to
show mercy toward prisoners and vanquished populations.
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Two A-20 Havocs from Ninth Air Force attack a French railyard during World War II. Despite the danger of civilian casualties, delaying German troop movements before the D-Day invasion was judged a military necessity. |
Aquinas in the 13th century refined Augustine’s principles into three
necessary conditions: War must be prosecuted by a lawful authority, which is
empowered to wage war; the war must have a just cause; and it must intend “to
achieve some good or to avoid some evil.”
As Europe’s wars of religion tapered off, the sovereign state became the
primary agent of right and wrong in warfare. The state shouldered the moral
responsibility for wars. Cicero founded his view of just war on the idea of
a human society with norms and morals that transcended the jurisdiction of individual
states. Dutch philosopher Hugo Grotius extended this notion in his 17th century
concept of natural law with binding, universal norms for behavior in war that
applied to all humanity. Governments and rulers might change, but the society
of man still demanded restraints on conduct.
For Grotius, wrote legal scholar Mark Edward DeForrest, a war was just if it
met three basic criteria:
The Nuremberg tribunal after World War II again acknowledged the concept of
customary internal law, universally applicable and recognized regardless of
the state’s legal system.
Traditionally the law of war boils down to two concepts: jus ad bellum, which
includes a just cause, competent authority, and right intention; and jus in
bello, or justice within the way the war is waged. In practice, the guiding
principles of jus ad bellum and jus in bello intertwine. Striking the wrong
target and causing unnecessary civilian deaths can weaken international or domestic
support for a war. A perception of poor conduct by a belligerent erodes the
just cause of the war and undermines its legitimacy because causing unnecessary
deaths or damage is seen as counter to international norms and customs. In modern
coalition warfare, attention to the law of war is a strategic imperative.
The International Conventions
A second and far more detailed level of the law of war focuses on operations
and tactics.
Criteria for lawful targets date to the 19th century. The first Geneva Convention
“for the amelioration of the condition of the wounded in armies in the
field” was promulgated in August 1864 (although not ratified by the US
until 1882). Subsequent Geneva Conventions form the present-day basis for protocols
against chemical weapons and for proper treatment of combatants, noncombatants,
and prisoners.
The law of war has been polished over and over again in attempts to cope with
mass warfare, destructive new weapons, and evolving international norms. Early
efforts sought to ban new modes of warfare. The Hague Conventions of 1899 and
1907 updated a series of rules and limitations on the conduct of war and the
behavior of the victors when they occupied territory. The desire of the High
Contracting Parties was to “diminish the evils of war, so far as military
necessities permit.” They listed rules on the treatment of prisoners of
war and on the use of bombardment and “poison or poisoned arms” and
defined who could be considered a spy.
Attack of undefended areas was specifically outlawed by Article 25. Naval bombardment
was the primary threat at the time, but the language presciently made room for
air warfare as it decreed that the “attack or bombardment, by whatever
means, of towns, villages, dwellings, or buildings which are undefended is prohibited.”
The Hague Conventions also outlined protections for significant sites. Article
27 of the 1907 convention stated: “In sieges and bombardments all necessary
steps must be taken to spare, as far as possible, buildings dedicated to religion,
art, science, or charitable purposes, historic monuments, hospitals, and places
where the sick and wounded are collected, provided they are not being used at
the time for military purposes.”
The law of war is in many ways sympathetic to attackers. As the 1907 Hague
Convention warned: “It is the duty of the besieged to indicate the presence
of such buildings or places by distinctive and visible signs, which shall be
notified to the enemy beforehand.”
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The Vietnam War featured some of the harshest aircrew restraints in history. Restrictions imposed by the nation’s civilian leaders went well beyond the law of war and exposed service members unnecessarily to risks. |
Just seven years after this international flurry of activity, World War I erupted,
introducing many of the new weapons anticipated in the Hague treaties. The violence
of that war led in two directions. First, several nations, after World War I,
outlawed war altogether. Nine nations signed the Kellogg–Briand Pact of
1928, which renounced war “as an instrument of national policy.” The
sentiment did not last. All the signatories (except Czechoslovakia, which was
occupied by Nazi Germany) later fought in World War II. Second, the world’s
nations produced the 1928 Geneva Convention, which ruled out the use of chemical
weapons. Remarkably, although all sides held stockpiles of chemical weapons,
none were employed on the battlefields of World War II.
However, that war set a new standard for brutality in other areas. One reaction
was the formation of the United Nations. Another was the Geneva Convention of
1949, which made modifications to the laws of war that took great care to protect
human rights.
To be called lawful, targets had to fall within these rules and other new concepts
of just war laid down in the post–World War II updates of the Geneva Convention.
One of the most important of these new concepts was proportionality. In 1977,
Protocol I to the Geneva Convention stipulated that attackers had to “take
all feasible precautions in the choice of means and methods of attack, with
a view to avoiding, and in any event, to minimizing, incidental loss of civilian
life, injury to civilians, and damage to civilian objects.”
Twentieth century warfare put airpower in the spotlight. Reactions to the RAF
firebombing campaigns in Germany and to similar tactics in the Pacific war led
to decades of postwar debate on what truly constituted lawful targets for air
warfare. With nuclear weapons looming in the background, making the case for
lawful bombing targets became part not only of just conduct of the war, but
also of the whole underlying rationale for going to war in the first place.
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Images such as this one—the view as an F-117 fighter’s precision munition homes in on a target during Operation Desert Storm—drew attention to the possibilities of high-tech targeting systems. |
Applying the Law of War
It is not attorneys and judges who apply the law of war. That job falls to
political and military leaders, and the law of war is a direct concern for both.
Both jus ad bellum and jus in bello make commanders and political leaders sensitive
to the concepts of military necessity and proportionality. Staying within the
bounds of the law of war is a key ingredient in keeping up support for waging
war in the first place. Sometimes, political concerns prove to be even stronger
as a force for restraint than the law of war itself.
In the spring of 1944, the Allies planned attacks on the French and Belgian
railway systems to constrain German troop movements before the Normandy invasion.
Statisticians estimated that such attacks could cost 80,000 civilian lives.
Gen. Dwight D. Eisenhower, the Supreme Allied Commander, and his air commanders
challenged those numbers and took the precaution of selecting targets away from
population centers wherever possible and warning civilians to stay away. The
Allies were well within the limits of military necessity. As British Prime Minister
Winston Churchill said at the time, humanitarian concerns were part of the picture,
but it was also an issue of “high state policy” not to embitter the
French.
Generals and admirals in command of operations have a direct stake in such
matters. “You’d have to be crazy not to consult the lawyers since,
if you violate the Geneva Conventions, you can be indicted as a war criminal,”
said one senior officer in Operation Desert Storm.
Ironically, the early Hague conventions wanted to set up comprehensive rules
so that unforeseen cases arising in battle would not “be left to the arbitrary
judgment of military commanders” as it was phrased in 1907. However, because
criteria such as military necessity and proportionality are central to keeping
the conduct of war within lawful bounds, the commander’s judgment is a
vital factor.
Take, for example, the Rolling Thunder bombing campaign in Vietnam. “Rolling
Thunder was one of the most constrained military campaigns in history,”
noted Army lawyer W. Hays Parks in a classic study of that operation. “The
restrictions imposed by this nation’s civilian leaders were not based on
the law of war but on an obvious ignorance of the law—to the detriment
of those sent forth to battle.” One example of this concerned an off-limits
hospital complex at Viet Tri. “If it was in fact a hospital,” said
one pilot, “it must have been a hospital for sick flak gunners, because
every time we looked at it from a run on the railhead, it was one mass of sputtering,
flashing gun barrels.” Parks noted that the 1949 Geneva Convention discontinued
protection for hospitals being used for “acts harmful to the enemy,”
presumably including anti-aircraft fire. “Given the insistence on widespread
photographic coverage of air strikes over North Vietnam, US demands could have
been made for cessation of the use of hospitals as AA sites, accompanied by
the publication of photographs of the sites,” contended Parks.
In 1991, Operation Desert Storm was designed to be everything that Vietnam
was not: decisive, rapid, and waged with a broad coalition of allies and at
the least possible cost. The law of war—at least within a broad understanding—was
carefully observed from the start. President George H.W. Bush instructed planners
to make sure religious and cultural sites in Iraq were not on the target list.
Strategic targets were chosen for military reasons but with an eye toward minimizing
overall destruction to Iraq. The special planning group in the “Black Hole,”
the main coalition air planning center in Riyadh, Saudi Arabia, had a military
lawyer on staff to render an opinion on the legality of strategic targets.
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In 1995 NATO responded to Serb attacks on civilians in Bosnia with Operation Deliberate Force air strikes against military targets. Here, an American soldier checks out a Serb tank stopped in its tracks. |
Limiting Collateral Damage
“Every target was examined on how to approach it with minimum loss of
life,” recalled retired Gen. Charles A. Horner, the commander of coalition
air forces for the operation.
Key allies such as Britain were consulted about sensitive topics such as potential
fallout from targeting chemical and biological weapons storage bunkers.
Control over lawful targets for air strikes became more intense as the war
continued. The bombing of the Al Firdos command post bunker on Feb. 13, 1991,
was one of the war’s major targeting controversies. Unknown to the coalition,
hundreds of civilians were inside the bunker on the night it was attacked. Although
the Al Firdos incident was an accident, not a violation of the laws of war,
bombing Baghdad was almost put off-limits. “Targeting in the Baghdad area
all but stopped, and General Schwarzkopf began to anguish over every target
we nominated,” Horner later said. Gen. Colin Powell, Chairman of the Joint
Chiefs of Staff, put targets in downtown Baghdad off-limits. Air planners worked
around it by defining Baghdad as anything within only a three-mile radius of
the city center.
In this case, senior military leaders went well beyond what was expected by
the law of war and kept targets off the list. Those very commanders that the
1907 Hague Convention did not trust turned out to be the most powerful agents
of restraint.
The perceived force of public opinion and interallied politics drove strategy
again during Operation Allied Force, NATO’s 1999 air war over Serbia. Estimates
of collateral damage and casualties were made for nearly every fixed target.
In the air-only campaign, each fixed target in Serbian territory had to be approved
via a complex, two-week process. Politics, not the dictates of international
law, weeded them out.
For example, on April 6, 1999, 222 targets were submitted to Gen. Wesley K.
Clark, Supreme Allied Commander Europe, but only 173 made it through the full
approval process at the North Atlantic Council.
The White House was not an impediment. Secretary of Defense William S. Cohen
testified to Congress that President Clinton approved all targets presented
to him by the Chairman of the Joint Chiefs of Staff, Gen. Henry H. Shelton.
However, the allies disapproved quite a few targets.
The mistakes of the NATO air war—from the accidental bombing of refugee
vehicles in a convoy to the accidental bombing of the Chinese embassy in Belgrade—kept
the air war under the microscope of international public opinion. Despite the
use of precision weapons, every stray bomb caused a surge of doubt about the
conduct of the war. Indeed, the concerns about political impact greatly exceeded
the restraint imposed by reasonable precaution in the laws of war.
Laws of war and self-imposed targeting restrictions mingled again during Operation
Enduring Freedom in 2001–02. Those at the combined air operations center
who saw the tactical picture made their frustrations known.
The target calculus in Operation Enduring Freedom was dictated, it appeared,
by an intense desire on the part of senior Pentagon and White House officials
to wage the war carefully. Targets were carefully scrutinized by Gen. Tommy
R. Franks, US Central Command’s commander, the Pentagon, and the White
House. “I think it’s important to say that the targeting by the United
States and by coalition forces has been very careful,” Defense Secretary
Donald H. Rumsfeld told CNN in October 2001. “It’s been very measured.”
Cultural and civilian sites were kept off-limits. The policy goal of minimum
destruction seemed to be just as important as the broad laws of war in the target
selection process. Commanders struggled to ensure that targets hit to support
Northern Alliance ground forces stuck to military necessity.
The law was no bar to use of the most modern weapons. Said legal scholar Danielle
L. Gilmore, who performed a study of lawful targeting in Desert Storm: “Nothing
in the law of war regulates the type of weapon that must be used when specifically
attacking particular targets. The applicable law only mandates a balancing of
military necessity and unnecessary suffering so that the concept of proportionality
is followed. The rule becomes one of reasonable precaution.”
By this criterion, the precautions taken more than upheld the laws of war.
“To the extent that there have been significant military targets in areas
that do have population nearby,” said Rumsfeld, “they have almost
always been targeted with a weapon that has a high degree of precision so that
there will not be a high amount of collateral damage.”
Accidental strikes did happen. Yet one incident—the mistaken October 2001
strike on a compound with a Red Cross warehouse—pointed up the obligations
of the defenders to do their part. A Pentagon spokesman explained that the International
Committee of the Red Cross warehouses were targeted by US forces because the
Taliban used them for storage of military equipment. Commingling food aid and
military vehicles—even if one building displays the red crescent—goes
against the grain of the laws of war. In this case, the strike was inadvertent,
but it pointed out that the defenders were not upholding their end of the laws
of war. Military vehicles had been seen in the vicinity of these warehouses,
according to the Pentagon.
US forces intentionally struck only military and terrorist targets, said the
spokesman.
The US code of conduct also led to the intense scrutiny of targets such as
civilian vehicles or buildings thought to harbor terrorist leaders. Military
necessity depended on the commanders’ judgment, and in Operation Enduring
Freedom, commanders chose to take time and exercise caution in identifying lawful
targets.
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An F-16 of the 510th Fighter Squadron, Aviano AB, Italy, flies an Allied Force mission. In the 1999 NATO air war over Serbia, each target had to be approved through a two-week process governed mostly by politics. |
The Future of Lawful Targets
Twenty-first century warfare will hold new challenges when it comes to space
operations and information operations.
Space law started with Sputnik and is already nearly 50 years old. “There
is probably no other field of human endeavor that produced so much international
law in such a short period,” noted a 1999 Defense Department general counsel
study. Unique to space law is the principle of noninterference, which holds
that nations in peacetime must not interfere with the operation of each other’s
satellites in space. However, in wartime, laws on the use of force again apply.
As the general counsel report noted, “The existing treaty restrictions
on military operations in space are in fact very limited.”
Information operations broaden the scope by raising new questions about what
exactly constitutes use of force. In 1998, Russia attempted to get the UN to
outlaw information warfare, but the UN passed only a weak resolution the following
year and other member states declined to follow up. For now, information operations
remain subject to a commander’s judgment on the same principles of necessity,
proportionality, and discrimination that guide traditional use of force.
Terrorists and other unconventional adversaries will not observe any of these
laws. But highly refined concepts of what constitutes a lawful target are deeply
ingrained in the American military. High-visibility campaigns and instant media
reporting simply underline the need to exercise great care, on political as
well as legal grounds. The laws of war leave plenty of room for commanders to
judge when a target must be struck due to military necessity. Yet recent experience
emphasizes that American commanders, at least, err on the side of caution and
respect.