The air force tested its heaviest bomb - a 21,500-pound (9,752 kilo) satellite guided behemoth - at a Florida range Tuesday in a show of devastating force as US forces mass for war against Iraq, officials said.
The Massive Ordnance Air Blast (MOAB) bomb, known informally as the "mother of all bombs," surpasses the 15,000-pound "daisy cutter" as the largest conventional bomb in the US inventory.
"This is not small," US Defense Secretary Donald Rumsfeld told reporters.
General Richard Myers, the chairman of the Joint Chiefs of Staff, would not say whether the new weapon would be deployed to the Iraq theater.
"But obviously, anything we have in the arsenal, anything that's in almost any stage of development could be used. We did that in Desert Storm with Joint Stars. We could do that with capabilities here," he said.
Rumsfeld treated the event as just another weapons test but acknowledged that Washington is seeking to exert maximum pressure on Iraq.
"The goal is to have the pressure be so great that Saddam Hussein cooperates," he said.
"Short of that, an unwillingness to cooperate, the goal is to have the capabilities of the coalition so clear and so obvious that there is an enormous disincentive for the Iraqi military to fight against the coalition and there's an enormous incentive for Saddam Hussein to leave and spare the world a conflict," he said.
The massive explosion - of what the Air Force termed "the largest non-nuclear conventional weapon in existence" - sent up a huge mushroom cloud over a test range at Eglin Air Force Base in Florida and sent tremors through the surrounding area.
A spokeswoman at Eglin said the bomb was tested just after 1800 GMT.
"It did go off," she said.
Military sources said residents over a broad area of Florida were forewarned of the impending blast lest they mistake it for an earthquake or tornado.
"It could be used as a pretty devastating weapon against ground troops, a psychological weapon," said Jake Swenson, another air force spokesman at the base.
"Any weapon of that magnitude will create a mushroom cloud, depending upon the debris on the surface," he said.
The smaller "daisy cutter" was used in Vietnam to clear jungle for helicopter landing pads, in the 1991 Gulf War to clear minefields, and in Afghanistan to clear caves and strike fear in al-Qaeda and Taliban fighters.
Development of the bomb began last year at the Air Force Research Laboratory at Eglin last and was due to be completed late this year.
The MOAB has a satellite guidance system and a tail kit to steer it to within about 13 meters (14 yards) of its target.
It is so big it is pushed out of the back of a C-130 cargo plane.
"It's on a pallet. A parachute drags the pallet out, and the bomb swings off the pallet. The pallet continues on down on parachute. And the bomb goes along its merry way with GPS," Swenson said.
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