By Jonathan Marcus
BBC defence correspondent
Air strikes in the no-fly zone have taken on a new dimension
Just a few days ago, almost unnoticed by the headline writers, US warplanes fired what may be the first shots of the coming Iraqi conflict.
US and British air strikes against Iraqi targets in the northern and southern no-fly zones are nothing new, although the scope and regularity of these attacks has been increasing.
But what makes this week's bombing different is that the target was not air defences, but ground-to-ground missiles.
According to US European Command, the missile systems were attacked just south of the northern Iraqi city of Mosul.
And US Central Command says that a similar target was hit in southern Iraq near Basra.
The weapons in question are reported to be Astros-2 rocket systems with a range of up to 37 miles (60 km).
The Astros-II is a Brazilian-made multiple-rocket launcher carried on the back of a large truck.
Some US experts claim the al-Samoud could carry bio-chemical weapons
More than 60 of the systems were sold to Iraq during the 1980s and the Iraqis may have manufactured a version themselves, under licence, known locally as the Sajil-60.
Iraq's overall holdings of the weapon are unknown.
Iraq' movement of these missile systems is interesting, suggesting perhaps the start of some deployments to counter a potential US and British attack.
But they also highlight the important role that artillery and long-range rocket systems have for the Iraqis; not least because they are deprived of any significant air-to-ground capability due to the dominance of US air power.
This is all going to feed into the debate about the longer range al-Samoud II missile system which chief United Nations weapons inspector Hans Blix has demanded the Iraqis destroy.
The UN says that these weapons significantly exceed the maximum range of 93 miles (150 km) permitted to Iraq under the UN disarmament resolutions.
The al-Samoud is an antiquated system and, by modern standards, has questionable accuracy.
Accordingly, some US experts believe that this could mean that its real military utility might be to carry chemical or biological warheads which would be effective even if they landed in the general vicinity of the target.
Such a weapon could be used against concentrations of troops in assembly areas, for example, during the early stages of a conflict.
Again it is not clear how many of the al-Samoud II's the Iraqi army has deployed.
The fate of the al-Samoud looks like turning into the test case for Iraq's compliance or non-compliance with its disarmament obligations.
But some military insiders believe that it could turn out to have a significant military role in any conflict, which probably explains Iraq's reluctance to agree to Mr Blix's demands.