The Pentagon and British defence sources indicated that they were ready and determined to strike if ordered to because Iraq did not obey the ultimatum issued by four of the five members of the UN Security Council. For the first time, the US admitted officially that F-117 Stealth fighters - the high-precision night-attack aircraft - were in the area.
The demarche issued at 10.15pm GMT on Wednesday demanded that all the missiles which had been moved to new positions south of the 32nd parallel should be moved to new sites; that Iraqi aircraft should not fly south of the parallel and that Iraqi forces should not take hostile action by, for example, tracking or locking radar on to allied aircraft. The Iraqis responded by stating their right to move their forces on their own territory, including deploying their own air defences.
Since before Christmas Iraq has made a systematic effort to violate the no-fly zone south of the 32nd parallel and to threaten allied aircraft enforcing it.
The missiles are three to five batteries - the number of launchers in each unspecified - of ageing but still potentially dangerous SA-2 and SA-3 missiles. They have been moved a 'few tens of kilometres' south of 32 degrees.
They are on mobile launchers and are routinely resited. They can be dismantled, transported and reassembled elsewhere in less than 12 hours. Western analysts said the reported movement of missiles on Thursday was therefore not a particular signal indicating that they were being withdrawn. Allied intelligence saw 'preparation of missiles and the associated radars for dismantling', but this was not especially surprising.
An allied attack was expected to concentrate primarily on the missile sites and associated radars. The Iraqi airfields under the no- fly zone south of the 32nd parallel have been dormant, and the incursions into the zone, of which there have been several in recent weeks, have been by aircraft based north of it. The closest operational airfield is al-Jarrah. But the allies have no remit to attack airfields north of 32 degrees unless they are expected to pose a threat to allied planes. As the allies also found early in the Gulf war, the 30-plus main Iraqi airfields are so large - bigger than London's Heathrow in many cases - that it would be impracticable to close them down completely.
The allied air power in the region is overwhelming. Armed with anti-radar missiles to home in on any radars that are switched on, and laser-guided bombs, the allies can hit the Iraqi positions from 'medium altitude' - around 15,000ft - out of range of the anti-aircraft guns which did most damage to low-flying aircraft in the 1991 war. The US has 12 ships in the Gulf itself, including the aircraft carrier Kitty Hawk, three cruisers, two destroyers and two frigates.
The Pentagon said yesterday the cruiser Cowpens and the destroyers Hewitt and Stump were equipped with Tomahawk land- attack cruise missiles which could also pinpoint targets.