...and the war machine
101st Airborne
US Marines
Cruise missiles
Iraq's Republican Guard
Australian special forces
British forces
Patriot missile defence
B-52 Stratofortress
101st Airborne
The 101st Airborne is the world's only air assault division and is capable of deploying thousands of troops deep behind enemy lines with unrivalled speed.
Known as the Screaming Eagles, the division has more than 280 helicopters, including three battalions of Apache attack helicopters.
The flexibility of the 101st Airborne's three divisions makes them highly-prized tactical assets much in demand from battlefield commanders.
Many analysts believe the 101st would be certain to be used in a ground war against Iraq, as it was during Operation Desert Storm in 1991.
Then, soldiers from the 101st were ordered to go deep into Iraq and set up a forward base with more than 2,000 men, 50 transport vehicles, artillery and tonnes of fuel and ammunition.
Editor of Jane's World Armies Major Charles Heyman - who served with 101st Airborne on attachment from the British Army in the early 1980s - described the division as "a highly effective and mobile unit" with a "glorious history".
"They are highly motivated, they have extremely good officers and NCOs and they are part of the elite of the US Army.
"Their key strength is their flexibility and their ability to be at the scene of action terribly quickly."
"If the US was attacking Basra, for example, it would be extremely useful to deploy a brigade of the 101st in a blocking position, 10 or 15 miles behind the main force, to prevent a counter attack from the rear," said Mr Heyman.
Soldiers from the division's 187th brigade were in Afghanistan as part of the forces trying to track down small groups of remaining men from Al-Qaeda and the Taleban.
History
The division is based at Fort Campbell, Kentucky, the US Army's third largest post behind Fort Bragg and Fort Hood.
One of its finest hours came during World War II, when the 101st led the way on D-Day in the night drop prior to the invasion.
They also showed bravery during the Battle of the Bulge. It was at Bastogne where Brig. Gen. Anthony McAuliffe refused to surrender to the Germans during their intense counter-attack and the Screaming Eagles fought on until the siege was lifted.
A key part of the 101st's training regime is the 14-day Sabalauski Air Assault School where soldiers learn the technical skills and logistics required to move up to 5,000 troops up to 250km in just a couple of hours.
The course combines combat assault training, slingload operations and a rappelling phase.
Soldiers must also complete a 12-mile road march with a fully laden rucksack and assault rifle within three hours.
Key aircraft used by the division:
AH-64 Apache - an advanced attack helicopter is flown by nearly all of the division's units. It can reach speeds of nearly 200mph, routinely carries Hellfire missiles, FFAR rockets and a chain gun.
UH-60 Black Hawk - a division workhorse, used in the combat assault squad transport mode. The helicopter can be configured as a Medevac aircraft and can fly at speeds greater than 180mph.
CH-47 Chinook - This veteran aircraft is a tandem-rotor medium transport helicopter that can lift eight tonnes and cruise at speeds topping 150mph.
US Marines
United States Marines are among the elite of America's fighting forces. As a unit these highly trained soldiers are used to spearhead American military campaigns.
Often called on in crisis situations Marines refer to themselves as America's "911 Fighting Force".
Uniquely the Marines are able to launch expeditionary military forces from land, sea or the air. Their relatively small number, 170,000, makes the force exceedingly nimble.
Both men and women can join the Corps, to find out more about their equipment, training and pay use the links above.
Cruise missiles
Cruise missiles can be launched from ships, subs and planes.
Cruise missiles have been a key part of major American military campaigns since the 1991 Gulf War.
But the term itself is generic, referring to self-propelled guided weapons which fly like normal aircrafts for most of their flight.
The simplest cruise missiles (developed by the Chinese) have a range of approximately 60 miles (100 km).
The US arsenal includes weapons that can be fired at targets from up to 1,500 miles (2,413 km) away yet land with a claimed accuracy of a few metres.
Each costs more than $1m, although planned new Tomahawk missiles will be less than $600,000 a piece.
Iraq's Republican Guard
The Republican Guard (RG) is the elite force of the Iraqi military.
Members of the RG are better trained, disciplined, equipped and paid than ordinary Iraqi soldiers.
There are doubts over the degree of loyalty Saddam Hussein can expect from the RG if they are faced with the full might and absolute technological superiority of US-led forces.
The Iraqi military in general is much reduced compared to the forces that were easily defeated by the US-led coalition in 1991 and its equipment is old and decrepit.
Privileges
All RG troops are volunteers rather than conscripts.
Personnel recruited into the guard are given bonuses and subsidised housing.
Alongside the RG, the Special Republican Guard (SRG) is regarded as a highly trained and equipped force - and one whose loyalty the Iraqi leader can count on without question.
The SRG is overseen by Saddam Hussein's son, Qusay.
Iraq's elite forces
Republican Guard Special Republican Guard
- 50,000 men 10,000 men
- 6 Divisions
(3 armoured, 2 infantry,
1 mechanised) 4 brigades
- 400 tanks 100 tanks
Its primary mission is to protect the Iraqi leader and secure Baghdad, the Iraqi capital. It has military and intelligence responsibilities.
This force is seen as a crucial pillar maintaining Saddam Hussein in power.
Tikrit connection
SRG soldiers tend to be recruited from in and around Saddam Hussein's home town of Tikrit.
The clans in these areas have shown great loyalty to Saddam Hussein and his regime.
The SRG is the only significant military unit allowed into central Baghdad, apart from the intelligence services' military branches.
The SRG was at the centre of disputes between Iraq and the UN weapons inspectors in 1998, when the Iraqi authorities refused access to its facilities where proscribed weapons were believed to have been stored.
Should a US-led campaign to remove the Iraqi leader include a ground war, some military analysts believe US and UK soldiers might have to confront the SRG in street by street fighting in Baghdad.
Australian special forces
Australia has committed 2,000 troops to the war in Iraq, including some 150 members of the its special forces.
It's the country's largest military deployment since the Vietnam war, though members of the Australian Special Air Service Regiment were heavily involved in secret operations with their US and British counterparts in Afghanistan.
The countries elite special forces were born in the post-war period out of the Australian Defence Force's close relationship with the British SAS.
Australian special forces, like their counterparts from New Zealand have often been members of or served with British units.
In general terms, it is organised along similar lines to the British units with the SAS at the heart of operations.
It shares the same regimental badge (a winged dagger) and motto (Who Dares Wins) as the British. It has now started to develop new units as Australia expands its counter-terrorism military strategy.
The forces present in Iraq include members of the SAS plus a quick-reaction force drawn from the 4th Battalion Australian Regiment (Commando), all under the command of Brigadier Maurie McNarn.
While the SAS units are understood to be active in Iraq on covert target identification missions, the Commando unit in Kuwait was established to prepare for search-and- rescue operations deep inside enemy territory.
Australia was one of the first nations to sign up to President George W Bush's so-called war against terror and special forces and regular troops served in Afghanistan.
In October 2002, weeks after the Bali bomb that killed 88 Australian holidaymakers, Prime Minister John Howard announced his country would expand the special forces with a new counter-terrorism commando company.
There would also be a new special forces supremo, on the same level as the heads of land, sea and air forces, Major-General Duncan Lewis. That new unit is expected to add an extra 300 soldiers over 18 months.
Army chief Lieutenant General Peter Leahy recently told the Australian parliament that special forces were becoming the military's "force of choice" though he was concerned that too much was being asked of them.
The Perth-based SAS is not without controversy.
UN war crimes investigators have looked at claims that Australia SAS men were involved in the torture and killing of two pro-Indonesian militiamen during their 1999 peace-keeping mission to East Timor.
That claim sparked a further continuing inquiry within the Australian military.
Veterans have demanded the investigation be dropped because it could affect the operational abilities of those serving in Iraq.
British forces
3 Commando Brigade Royal Marines
3 Commando Brigade Royal Marines is the elite fighting force of the Royal Navy.
The 3,500-strong brigade is an amphibious rapid reaction force, highly trained for combat in extreme weather conditions and on difficult terrain.
The frontline of the brigade is made up of three lightly armed units - 40, 42 and 45 Commando - which each have about 700 members.
It maintains a state of permanent readiness to move anywhere in the world when the security of Britain and its allies is under threat, and can be deployed early when needed to indicate the UK's political and military will and capability.
Royal Marines spokesman Major Tim Cook told BBC News Online one of the most important aspects of the brigade was that it could be "poised" for action off a coast in international waters.
"They can sit, sail up and down the coast and exert pressure - they provide the pressure to back up the diplomacy."
3 Commando Brigade was formed during World War II, and played a prominent role in the D- Day landings.
It led the final assault on Port Stanley in the Falklands campaign of 1982.
It has also been deployed in Northern Ireland, Sierra Leone, and on peacekeeping missions in Bosnia, the Congo and Kosovo.
Most recently, 40 and 45 Commando have served in Afghanistan as part of the war on terror.
It is 40 and 42 Commando which are being sent to the Gulf as part of the largest British naval deployment for two decades, led by HMS Ark Royal.
Commando soldiers have to undergo what is recognised as one of the toughest infantry training regimes in the world, at the Commando Training Centre in Lympstone, Devon.
Much of the training is carried out on the rugged terrain of Dartmoor, and culminates in the Commando course - a series of tests of fitness, endurance and military professionalism.
While reluctant to sound to self-congratulatory on behalf of the Marines, Major Cook admitted the course was "tough", adding that when compared with infantry training around the world "very few other courses could stand up to it".
Royal Marines who pass the course win the prized green beret, and then normally join a Commando unit of 3 Commando Brigade, led by Brigadier James Dutton.
40 Commando is based near Taunton in Somerset, 42 Commando near Plymouth in Devon - where the brigade headquarters are also located - and 45 Commando at Arbroath on the east coast of Scotland.
The units undergo rigorous environmental training in either "hot, arid", "humid jungle" or "cold mountainous" conditions.
Usual training areas are in the Middle East, Belize or Brunei, and Scotland and Norway.
Patriot missile defence
The Patriot missile defence system is designed to detect and destroy incoming enemy tactical ballistic missiles, cruise missiles or aircrafts.
It comprises a radar, control centre and associated power supply and communications towers, and launchers on trucks.
The manufacturer says it can take 16 launchers, the US Army uses usually five to eight in a battery.
Each launcher holds four missiles - or 16 in the latest "Pac-3" version.
The launchers can be up to a kilometre away from the radar and control hub, linked by microwave signals.
The trailer-mounted radar is a "phased array" type - it scans the sky with a narrow beam which flicks between thousands of locations each second.
If it detects something, up to 62 miles (100 km) away, it focuses on it and relays information about it to the control centre.
It can track up to 100 targets and send guidance data for up to nine missiles.
B-52 Stratofortress
Introduced in 1955, the B-52 of Dr Strangelove fame was designed as the mainstay of the USA's long-range nuclear bomber force, but has been used in anger to drop conventional weapons.
In the Gulf War, B-52s dropped 40% of all coalition bombs. Carrying air-launched cruise missiles, they opened the attack on Yugoslav forces in the Kosovo campaign.
The bomber is almost 160 feet (49 metres) long with wings spanning 185 ft (56 m), eight turbofan jet engines slung under them in four pairs.
Top speed is only about 630mph (1,014 kph) but the B-52 has a range without refuelling of more than 8,000 miles (12,870 kms) with a 10,000 lb (4,536 kg) bomb load and can fly high, up to 50,000 ft (15,240 m).
It could also fly low, using terrain-mapping radar showing the ground up to 10 miles ahead of the aircraft - but this role has been dropped. The pilots wear night vision goggles to see in the dark.
There are six crew places on two decks but on the current version there are only five crews, since the job of rear gunner was dropped: Commander, co-pilot and electronic warfare officer, navigator and radar navigator, who delivers the weapons.
In its internal, 28 ft-long weapons bay and on pylons beneath the wings the current H version can carry a wide mix of bombs and missiles, such as 51, 500 lb (227 kg) bombs, 30 cluster bombs, or 20 cruise missiles.
The United States has 44 B-52s in constant readiness for combat use and the aircraft is expected to continue in service for another 40 years.
Source: Jane's Defence Group
