BY THREATENING military action - up to and including the use of Cruise missiles - in response to Iraq's offensive against Kurds in its northern provinces, the Clinton administration is basing a potential use of force on murky international legal grounds.
The US has for several years invoked UN Security Council Resolution 688, which in April 1991 condemned the Iraqi government's repression of minorities as an underpinning for creating no fly zones in the north and the southern parts of the country.
US officials argue now that Arbil, a stronghold of one Kurdish faction overrun by Iraqi ground forces on Saturday, violates that resolution.
But Resolution 688, while encouraging widespread relief aid to the Kurds by international organisations after the Gulf War, did not specifically set up a safe haven off limits to Iraqi troops. It also deliberately excluded military force.
China had threatened to veto any measure that would justify foreign military intervention during the debate on the resolution which the then French president, Mr Francois Mitterrand, insisted the council adopt.
In subsequent years, the United States and its allies kept their dealings with Iraq on the no fly zones away from the Security Council, thereby giving credence to those who maintained the West was stretching the interpretation of Resolution 688.
But at the same time, most council members turned a blind eye to exclusion zones, with many states believing that protection was necessary to prevent a humanitarian catastrophe following the Gulf War, which the UN authorised. The then Soviet Union supported the zones.
"It's a measure of Iraq's isolation and unpopularity that states are treating this as an exceptional case," one senior envoy said at the time.
Nevertheless, the US will have difficulties in crafting any kind of Security Council statement that might approve military action or obliquely lend credence to it. Officials were consulting with key council members all through last weekend.
Resolution 688 was adopted when Kurds in the north and Shi'ites in the south rose up against Saddam Hussein's government in the spring of 1991 after the Gulf War. The Kurds fled to Turkey and Iran, pursued by Iraqi troops and strafed from the air, prompting a worldwide outcry.
Shortly afterwards, the allies, as well as UN humanitarian groups, moved in to provide shelter for the Kurds and Iraq was warned not to fly any aircraft over the area.
In the summer of 1992, the allies cited the same resolution when they banned Iraq from flying over the southern marshes where Shi'ite rebels were hiding.
Iraq, however, has frequently pointed out the legal difficulties and did so again over the weekend.
Iraqi troops, backed by armour and artillery, intervened on Saturday on the side of Mr Massoud Barzani, leader of the Kurdistan Democratic Party (KDP), to recapture the Kurdish stronghold of Arbil from Mr Jalal Talabani of the Patriotic Union of Kurdistan (PUK), favoured by Iran.
The Kurds now number more than 25 million and are spread across the common border of Turkey, Iraq and Iran. In addition to Iraq, which used poison gas against Kurds in 1988, Turkey and Iran have conducted military campaigns against them within their respective territories.