Slowing the Allied Advance

Drawing on its experience during the gulf war, Iraq is not mounting a major defense of its borders. But it is taking several steps to try to bog down American and allied forces as they try to advance to Baghdad. Defense Department officials said Iraq had shipped rail cars full of ammunition and demolition equipment to its oil fields. That spurred concerns that Iraq planned to blow them up to hamper the invasion and portray it as an economic and environmental catastrophe.

United States officials said Iraq had also considered plans to destroy dams and flood the Euphrates River, a move that could make it more difficult for forces to cross the river, slowing an offensive. Iraq's 11th Infantry Division has been stationed near the city of Nasiriya, where it can try to put down a Shiite rebellion in the city and guard the crossing points over the river. Iraq has also moved some light infantry and artillery south to the Basra area.

"If hostilities begin, Saddam is likely to employ a `scorched earth' strategy, destroying food, transportation, energy and other infrastructures, attempting to create a humanitarian disaster significant enough to stop a military advance," Vice Adm. Lowell E. Jacoby, the director of the Defense Intelligence Agency, told Congress this week. He said the Iraqis would try to blame American forces for the damage.

Iraq is also positioning surface-to-surface missiles. Iraq has placed Al Samoud missiles north and west of Baghdad. American intelligence believes that the missile can travel much farther than the 90-mile range that is allowed by the United Nations. Iraq has also placed Ababil-50 and Ababil-100 missiles and Soviet-designed Frog rockets north of the capital. Defense Department officials say the missiles have been put in place both to strengthen Iraq's defenses in the north and to threaten population centers like Kirkuk and Mosul if they fall into the hands of American or Kurdish forces.

To threaten Kuwait and American forces there, Iraq has also deployed mobile missile systems in the south near Basra. On Tuesday, American and British planes attacked an Ababil-100 mobile missile system there, and on Wednesday they hit another. Those missile deployments, as well as the deployment of an antiship missile launcher near Basra that was attacked last month, showed an escalation in Iraqi preparations.

American intelligence reports that Mr. Hussein has authorized his commanders to use chemical and perhaps biological weapons. It is difficult for intelligence experts to determine if the munitions being sent to Iraqi forces have chemical or conventional warheads. But American intelligence has noted that protective gear against chemical attack has been given to Special Republican Guard forces as well as intelligence and security personnel charged with defending Baghdad and other cities. It has been given to some Republican Guard units outside Baghdad as well.

United States intelligence agencies have concluded that Iraq will try to use chemical weapons against American forces. The intelligence agencies believe that Iraq has a small covert supply of long-range Scud missiles, which can be equipped with chemical or biological warheads. The intelligence agencies believe it is likely that Iraq will try to fire them at Israel in an effort to portray the war as a battle with an American and Israeli coalition and build support in the Arab world.

Defending Baghdad

It is in Baghdad, however, where Mr. Hussein's administration is expected to make its last stand. A city of 4.5 million, it is a potential urban battleground where Iraq has its best command and control and most loyal forces. The Pentagon has received reports that the city is stockpiling food, apparently preparing for a long siege. The approaches to Baghdad are protected by three Republican Guard divisions: the Medina to the south, Al Nida to the east and the Hammurabi to the west. The Republican Guard is considered Iraq's most capable and loyal force.