At the main Serb checkpoint outside Sarajevo, the big Human to Human aid convoy stood stalled in its tracks. Sweating profusely, a uniformed Serb fighter pushed a wheelbarrow full of goods taken from one of the vehicles into the cellar of the house he and his comrades were using as a guardroom. Nearby, other Serb fighters were stacking cartons of the seized aid into a minivan.

Their commander was unapologetic. “According to the orders of the authorities of the Republika Srpska, 30 percent of the supplies in all aid convoys must be turned over to us.”

In fact, the Human to Human convoy was one of the few private aid convoys that ever made it to Sarajevo. But not intact. After losing 30 percent of its cargo at the first checkpoint, it was stripped of still more in the Serb-controlled suburb of Ilidza. In the end, only the flour and macaroni made it into the city.

Staff of the United Nations High Commissioner for Refugees (UNHCR) in Sarajevo were well aware that the Serb forces besieging the Bosnian capital were seizing humanitarian aid intended for civilians within the city. They should have been; more often than not, they were allowing the Serbs to take 30 percent of the goods UNHCR itself was bringing in as well. Under international law, the Serbs had every right to inspect all food and medical supplies being brought through their lines into government-controlled territory in order to satisfy themselves that the relief was destined for noncombatants rather than the Bosnian Army. They did not have the right to siphon off the food. Pillage is a war crime in an international conflict and a prohibited act in an internal conflict.

Starvation of civilian populations as a method of warfare is prohibited in both international or in internal conflicts, a prohibition stated explicitly in the two 1977 Additional Protocols to the Geneva Conventions. Yet a military force controlling the flow of relief supplies over routes or into territories it controls is under no obligation to do anything to support the military forces arrayed against it. The tension between these two positions has given rise to a complex series of rules that are difficult to implement without the use of force by the international community. The International Committee of the Red Cross (ICRC) takes the position that the fear of diversion to combatants provides no legal justification for refusing passage. But its position is not widely shared.

Humanitarian aid for civilians, under Article 23 of the Fourth Geneva Convention, enjoys the right of free passage through battle lines if intended for “children under fifteen, expectant mothers and maternity cases,” and a broader exemption can be made when all or part of the civilian population in occupied territory is “inadequately supplied.” Because of a very real military concern that the goods might be used to supply enemy armed forces, “inadequately” is understood in a strict sense.

It is, moreover, prohibited under Article 54 of Additional Protocol I to destroy “objects indispensable to the survival of the civilian population,” including foodstuffs and their production, drinking water, and irrigation works, or to undertake actions “which may be expected to leave the civilian population with such inadequate food or water as to cause starvation or force its movement.” Whether this prohibition on destruction of such objects extends to a positive obligation to allow their entry to provide for populations at risk of starvation is not clear from Article 54 but might be implied from subsequent provisions on relief operations.

If civilians in a conflict are not adequately provided with supplies, then under Article 70 of Protocol I “relief actions which are humanitarian and impartial in character and conducted without any adverse distinction shall be undertaken, subject to the agreement of the Parties concerned in such relief actions.” Short of conditions requiring supplies essential to the survival of the civilian population, relief operations are subject to agreement of the parties.

In an internal armed conflict, if the civilian population is suffering “undue hardship” due to a lack of food or medical supplies “essential to its survival,” relief actions “which are of an exclusively humanitarian and impartial nature” and conducted “without any adverse distinction” shall be undertaken subject to the the consent of the State involved.

Although the United States is not a party to Additional Protocols I or II, it supports the prohibition of starvation as a means of warfare.

It was in large measure because of the ambiguity in the law—the tension between military necessity and the obligation of all sides in a conflict to allow in articles needed to prevent starvation or the threat of starvation, so as to force civilians to flee their homes—that the United Nations and private relief groups in Bosnia were so vulnerable to the kind of blackmail I witnessed at the Serb checkpoint.

If allowing the Serbs to take 30 percent of the relief supplies meant that they would let in the other 70 percent when, strictly speaking, their obligation to do so was not ironclad, it was better to give in. Or so most aid groups reasoned. The alternative might very well have been to allow the most vulnerable groups—the very old and the very young, in particular—to starve. And more widespread starvation, which the humanitarian effort did manage to stave off in Bosnia, remained a possibility almost to the end of the war.

In Bosnia the signals were far from clear. The UNHCR and other agencies realized early on that it remained open to question whether the Serbs were obligated to allow aid though. Directives from the UN Security Council required as much, but realistically, they also knew they were incapable, as the law required, of preventing some of the aid from flowing to the Bosnian Army. Whatever the legal niceties, in all wars, the army eats first.

These were some of the reasons they acted as they did—another was that there was no will on the part of the UN or the great powers to push the aid through by force. Thus, trying to buy off the fighters seemed preferable to insisting that relief operations had to proceed in an absolutely uncompromising way.

“We could not let all those people die,” was the way one UNHCR official in Zagreb put it at the time, “so we closed our eyes to many things.” Loopholes in the law as well as realities on the ground had a lot to do with that decision.

(See humanitarian aid, blocking of; siege; water supplies and works, destruction of)