How Iraq is required, under international law, to treat U.S. civilians in Iraq and Kuwait depends on whether there is war or armed conflict between it and the United States. But the war does not have to be formally declared, according to international law experts.

The Iraqi government Saturday declared the U.S.-led naval blockade an act of war and said thousands of foreigners would be subject to rationing of food, medicine, clothing and other goods "fully equally" with Iraqi civilians. It emphasized that foreigners' babies would share the same hardships as Iraqi babies.

Iraq yesterday ordered U.S., British and French nationals to report to three hotels and said that U.S. and other captive citizens would be held at Iraqi military installations -- raising the possibility of using the civilians to deter a U.S. or allied attack.

If, as the United States has been saying, no war or international armed conflict exists, peacetime rules apply for the treatment of U.S. "civilians there for peaceful purposes," said W. Thomas Mallison, an international law specialist and professor emeritus at the George Washington University National Law Center.

In times of peace between the United States and Iraq, Iraq must treat foreigners, such as the U.S. civilians, no worse than it treats its own civilians or no worse than required by international "customary law standards," if those are higher, Mallison said.

Under peacetime rules, foreigners generally would have the right to travel, leave the country, move about freely, carry on normal business, live where they please -- except in sensitive military areas -- and retain possession of their money.

But Mallison said that if food and medicine were rationed in Iraq, there would be no legal reason why foreigners, including Americans, could not be subjected to it equally with Iraqis.

Regardless of whether the United States and Iraq are at war or peace, these same general rules would apply to citizens of third countries who are in Iraq and whose countries are not involved in the current dispute, Mallison said.

The situation is different under international law if there is war or armed conflict between the United States and Iraq, as the Iraqis claim. A blockade is generally considered to be an "act of war," Mallison said, and the United States has declined to characterize its current naval action as a blockade.

If there is a declared war or even an undeclared state of hostilities, then U.S. civilians in Iraq and Kuwait can be treated as enemy aliens who present a "security threat." They can be interned or their movements and rights to conduct business restricted, Mallison said. But they cannot be treated brutally or harshly or deprived of personal property, and they must be fed adequately, given medical treatment and not separated from their families, he said.

Francis Boyle, professor of International law at the University of Illinois College of Law in Champaign, said that under international law, use of force or threats of force to "interdict shipping" or "quarantine" a country is usually considered a blockade and an act of war, even if war is not formally declared.

Boyle said that by announcing Saturday that they considered the U.S. naval action an act of war, Iraq indicated it believes it has triggered its right to detain or intern U.S. civilians in Iraq and Kuwait.

Boyle, who is an adviser to Michael Saba, who recently escaped from Iraq by taxi and hitchhiking, said that since Iraq considers an act of war to have been committed, the United States is entitled to ask the International Red Cross under the Geneva civilian convention of 1949 to seek entry to Iraq and Kuwait to register the names of U.S. civilians detained or interned there.

Mallison cautioned, however, that by doing so the United States would concede that a war or armed conflict exists.

Boyle said any government is less likely to harm detainees whose names and presence have been recorded since it may later be called to account for their safety.

Boyle said he thinks it is crucial for the United States to immediately ask a neutral third country that has diplomatic relations with Iraq to serve as a "protecting power" to assure that the protections for detainees or internees are granted by Iraq.

Boyle added that he believes Iraq violated international law by moving U.S. civilians from Kuwait to Baghdad.

He said international law forbids deliberately using foreign civilians as a military shield or holding them hostage to obtain a political or other concession.