The new-generation weapons

Guided Bomb Unit-35 bombs being moved to a strategic point as a CH53D Sea Dragon helicopter takes off on the flight deck of aircraft carrier USS Constellation in the Gulf on December 24, 2002. - AMR NABIL/ AP

IF a war with Iraq breaks out, the United States is likely to use its non-nuclear penetrating weapons to strike Saddam Hussein's hardened and deeply buried targets (HBDTs). These air-launched munitions would include:

Guided Bomb Unit-24 (GBU-24): This 900 kg, laser-guided bomb is a precision weapon that, when outfitted with a BLU-109 penetrator warhead, can be launched at a low altitude of up to 16 km from the hardened target for stand-off strikes. About 1,200 GBU-24 bombs were used during the Gulf war. Enhancements of the GBU-24 in recent years include outfitting the weapon with the global positioning system (GPS) for increased precision. The U.S. Navy is developing a model of this bomb that includes a more sophisticated penetrator warhead, as well as a Joint Standoff Weapon in conjunction with the United Kingdom, for penetrating hardened targets.

Guided Bomb Unit-28 (GBU-28): This 2,200-kg bomb was developed especially to deal with Iraqi bunkers and command centres. The GBU-28 `bunker-buster' was designed in record time during the Gulf war after the U.S. military solicited proposals from industry a week after combat began, and the bomb was deployed within a month of beginning its construction. The 4,400-pound BLU-113 warhead, which has a reinforced steel casing, can penetrate more than 6.1 metres of reinforced concrete or 12,192 m of earth, with a range of 87 km. The GBU-28 has most recently been used in the war in Afghanistan to strike suspected Al Qaeda bunkers. Future U.S. Air Force development of this weapon includes loading a GPS-enhanced GBU-28 onto the B-2 fighter plane and expanded testing.

Bomb Live Unit-116 Advanced Unitary Penetrator (BLU-116 AUP): This warhead comprises similar flight characteristics as the BLU-109, but with an "advanced heavy steel penetrator warhead filled with high-energy explosives that can penetrate more than twice as much reinforced concrete as the BLU-109".

As the next generation of penetrator warheads, the 900 kg BLU-116 AUP will be part of the U.S. Navy's future development of the GBU-24 as it seeks to "minimise the collateral effects associated with counterforce operations against WMD related facilities". The newest weapons also incorporate the hard target smart fuze technology, which allows the AUP to be detonated at the optimal point for inflicting damage to the target.