The flurry of aerial destruction indicates that the insurgents have attained a new tactical plateau and may be using more advanced weapons systems to target the US occupation. Analysts are asking whether the insurgents are suddenly accessing greater numbers of man-portable air-defense systems (MANPADS) and from where. These shoulder-launched surface-to-air missiles typically use infra-red guidance and can
low-flying aircraft and helicopters.
"There is no question that advanced MANPADS are being used against US helos and that holding back on this strategy was intentional, so that the ramp-up would do the most damage to morale," said Don Weadon, a Washington-based international lawyer and Middle East authority. "It is a battle of wills, and against superior firepower one has to be cagey to the max."
The US military ordered changes in flight operations early last week but it was not enough to avoid the downing of a fifth helicopter on Wednesday. The crashes began on January 20 and follow insurgent claims that they have received new stocks of anti-aircraft weapons and a recent boast by Sunni militants that "God has granted new ways" to threaten US aircraft, according to the Associated Press.
"There's been an ongoing effort since we've been here to target our helicopters," said Major-General William Caldwell, the US chief military spokesman. "Based on what we have seen, we're already making adjustments in our tactics and techniques and procedures as to how we deploy our helicopters."
In the past, defensive measures have included flying lower and faster, varying routes and using zigzag patterns when traversing dangerous areas. US helicopters in Iraq are also armed with defensive aid suites (DAS), anti-missile systems such as flares and anti-heat-seeking devices.
The most basic DAS system includes a laser-warning detector and multi-spectral smoke and counter-fire as countermeasures. "DAS are only of use against guided weapons," said Spencer. "There's almost nothing that can counter a bullet in a soft spot, nor an RPG-7 fired at an airframe." RPG-7 is a handheld grenade launcher.
In December, Khudair al-Murshidi, a spokesman for Iraq's Ba'ath Party, announced that Sunni insurgents had received shoulder-fired anti-aircraft missiles, adding that "we are going to surprise them", in a reference to US forces.
Four of the helicopters crashed in Sunni areas, with another shot down during fighting between the US and Iraqi armies and cultists in the Shi'ite stronghold city of Najaf in southern Iraq.
"Until more is known about these apparent shootdowns, one cannot rule out a very old method," said Wayne White, a veteran State Department intelligence analyst, "a group of shooters with systems like the RPG-7, originally designed for use against various armored vehicles on the ground, fired simultaneously or in rapid succession at a helicopter at relatively low altitude, increasing the chances for a lucky hit."
This theory certainly appears to be borne out by witnesses. On January 28, a Reuters reporter witnessed the downing of the helicopter in Najaf. He described how a burst of machine-gun fire produced a trail of smoke from the helicopter before it crashed.
At the site of the most recent crash, Iraqi farmer Mohammad al-Jenabi described how the twin-rotor C-46 troop carrier came down. "The helicopter was flying and passed over us, then we heard the firing of a missile," he said. "The helicopter then turned into a ball of fire. It flew in a circle twice, then it went down."
The helicopter went down near the Sunni insurgent stronghold of Taji, about 30 kilometers northwest of Baghdad. Responsibility was claimed by the Islamic State of Iraq, an umbrella group of insurgents that includes al-Qaeda in Iraq.
"It's not that difficult to shoot down a chopper with small-arms fire," said a British officer serving in the Middle East, "especially if you take into account that the birds are slow and even a car driven fast can outpace them."
Insurgents have used SA-7s, a widely used shoulder-fired missile with an infra-red homing device, against US and British aircraft since 2003. But accusations that Iran is supplying this hardware are either false or irrelevant, according to Western analysts.
"Whether ... they're coming in from Iran - where the technology isn't that good - is not the case," said Weadon, the Middle East expert. "The MANPADS can either be leftovers in Afghanistan or of Chinese or Russian manufacture rolling in over from Saudi or even Turkey. I doubt that anyone would risk rolling them in over the highly scrutinized border with Iran."
Whatever their provenance may be, the introduction of advanced MANPADS into Iraq presents an unsettling echo from a previous occupation and a telling indication of where the current conflict may be headed. In 1980s Afghanistan, the invading Soviet army was similarly incapable of establishing its authority outside Kabul, forcing it to rely on its air force for transport.
Washington took advantage of this and supplied its mujahideen allies with US-made FIM-92 Stinger anti-aircraft missile systems with which to target its Cold War enemy. The mujahideen yielded the Stingers with unnerving accuracy and vastly increased Soviet losses. It was the single development that contributed the most to the Soviet withdrawal from Afghanistan.
ff The case of Darwinism - survival of the fitest. 
