Helicopters: Vital but vulnerable

By Jonathan Marcus BBC defence correspondent

The Black Hawk utility helicopter carries out a variety of roles from transport to casualty evacuation.

Iraq's size means mobility is all - ground movement is slower and US convoys often face attack from rocket-propelled grenades or road-side bombs.

But the downing of the Black Hawk comes less than a week after the shooting down of a much larger twin-rotor Chinook helicopter.

It was the most costly single attack since Saddam Hussein's regime fell.

Helicopters are an essential element of America's military operations in Iraq. But they are inherently vulnerable to ground fire.

Helicopters can easily be shot down by small, portable surface-to-air missiles

This was shown dramatically during the invasion of Iraq, when a large offensive by a unit of much more agile American attack helicopters had to be aborted due to the intensity of anti-aircraft fire.

That episode prompted the military authorities in a number of countries to look again at the much-vaunted qualities of the modern attack helicopter.

But for current operations in Iraq the helicopter is irreplaceable.

In practical terms, US commanders will want to review the way in which helicopters are operated to see if anything can be done to make them less vulnerable. There may be calls for counter-measures against attack to be improved.

But helicopters can easily be shot down by small, portable surface-to-air missile systems.

Public perceptions

But these attacks also highlight the essential imbalance or asymmetry of the struggle between the Iraqi guerrilla fighters and the occupying US forces.

Factfile: Black Hawk

America may be the greatest military power on earth but individual vehicles, helicopters - even battle tanks - are vulnerable to ambush or surprise attack.

These incidents inflict a steady trickle of US casualties. They may or may not have an impact on the wider course of events in Iraq - it is too early to say.

But the problem for the Americans is that they cannot make themselves invulnerable. The guerrillas' objective is simply to inflict casualties.

For this is a war as much about perceptions as reality.

The Bush administration is clearly uncertain about how to deal with the regular drumbeat of casualties in Iraq - a situation made worse by the fact that a presidential election is looming.

And American voters seem increasingly uneasy about the way things in Iraq are heading.

More US troops have been killed since President George W Bush declared an end to major combat operations than died in hostilities during the invasion of Iraq itself.

American attitudes are complex. Ordinary Americans do not want to see their army chased out of Iraq. Many people still feel, as does President Bush, that there is a job to be done.

But there is a growing gap between the Bush administration's claims of success in the rebuilding effort and the sorts of news stories that most Americans see.

The administration has chosen to blame the messengers - the media - for somehow distorting things.

But however localised the US military's problems are in Iraq, those problems are real enough. The steady return of body-bags to the US proves that.

In Iraq itself this episode will only add to perceptions of US vulnerability. But the calculations here are equally complex.

Shadowy opposition

Recent bomb attacks by Iraqi insurgents have killed more ordinary Iraqis than Americans.

It is not clear who exactly is behind these attacks. And it is equally unclear in whose name they are being carried out.

In this sense it is hard to speak of "an Iraqi resistance".

There are clearly loyalists who miss the old regime; there may well be foreign fighters who have come into the country specifically to target Americans, as the Pentagon asserts.

But how far such groups can claim real public support is hard to say. Many Iraqis may be unhappy with the US presence and alarmed by the uncertainties and insecurities that "liberation" has brought.

But this does not necessarily mean they support a full-scale guerrilla war against the Americans and certainly not a guerrilla war where, as often as not, the casualties are Iraqi rather than American.