The Iraqi regular army - apart from the Republican Guard and other special units - is believed to consist of 17 divisions, each with about 10,000 men.
Seven are infantry divisions, three are mechanised and three have heavy armour - tanks.
A report from the Jane's group on 18 March quoted "intelligence sources" as saying the latest deployment involved about 2,200 tanks and 3,800 armoured personnel carriers.
The US defence department has estimated that they also have about 2,000 artillery pieces.
Iraqi regular army
North
1st Corps
guards Turkish border and edge of Kurdish enclave
5th Corps
defends the border with Syria and Turkey
East
2nd Corps
protects area east of Baghdad from Iran
South
3rd Corps
guards the border with Kuwait
4th Corps
defends the border with Iran
Source: Jane's, CSIS
About 85% of the army are conscripts, who serve for between 18 and 24 months depending on their level of training and expertise.
"Most of them don't want to be there," said the editor of Jane's World Armies, Major Charles Heyman.
"The army itself is in a deplorable state, it's got a lot of 1960s, early 1970s equipment, most of which has had no spare parts or replacements since the Gulf War.
"They are way down the feeding chain when it comes to any sort of military equipment whatsoever and we haven't actually seen any real evidence of the Iraqi army having been out training for a very, very long time."
Propaganda effort
The hope among coalition planners is to persuade the army to stay in barracks.
Coalition aircraft have been dropping leaflets telling ordinary soldiers to keep out of the conflict.
One said they should "not risk their life and the life of their comrades" and should "leave now, go home, and learn, grow, prosper."
"I think probably from the point of view as an effective military fighting force, you probably can take the majority of the army out of this," Major Heyman said.
But not all of it.
Anthony Cordesman of the Centre for Strategic and International Studies (CSIS) in the USA agrees that the infantry divisions are of low quality and may well either do nothing or even defect.
Reserve forces, while theoretically capable of perhaps trebling the size of the army, are of doubtful loyalty, not least because of Iraq's ethnic splits.
"Its regular heavy divisions, however, have fought well in the past, proved loyal during the Iran-Iraq War, and many units retreated effectively during the Gulf War and uprisings that followed," he said.
Some units might also be willing to fight urban warfare in a "final circle" centred on Baghdad.
Morale
Colonel Christopher Langton of the Institute for International and Strategic Studies also cautions against being too dismissive of the regular army.
"They are the home team - and home teams play better at home," he said.
"If you look at the way they have been deployed, many are in their home areas probably to strengthen this factor."
There had been attempts to boost morale. The heads of the armed forces' officer training colleges had sought to persuade men that if they served loyally, their families would get special financial support if they needed it.
"This is obviously because somebody has deserted or something, so they sat round a table with Saddam Hussein and made this announcement to the country."
Officers were professionals with a long tradition and established ethos and were of reasonable standard. In the past, many trained in the UK.
"But over the last few years they have suffered from a dearth of equipment and probably an inability to train properly."