The Bush administration is putting the finishing touches to plans for a massive land, air and sea attack on Iraq, should the United Nations inspectors fail in their mission. 

It would involve up to 250,000 US and British troops and amount to a modern-day Blitzkrieg, aimed at forcing the speedy collapse of Saddam Hussein's regime with as few casualties as possible among Allied troops and Iraqi civilians. 

The campaign would begin with an aerial bombardment, shorter but more precise and even more intense than the month-long bombing that kicked off Operation Desert Storm in January 1991. The onslaught would begin against "regime targets'' concentrated on Baghdad and the central parts of the country, and American and British forces would seize the northern, western and southern sections of Iraq. 

The leak of the plans – reported in very similar terms by both The Washington Post and The New York Times yesterday – is plainly a deliberate attempt to step up the pressure on President Saddam to comply with Friday's unanimous UN Security Council resolution, which orders unfettered and complete access for the weapons inspectors. 

The Pentagon continues to send men to the Gulf. More than 50,000 American troops are already in the region. Two additional aircraft carrier groups are on their way while heavy equipment is being shipped in by chartered freighter. The overall effect is to reinforce the sense that conflict is inevitable whatever happens with the inspections. Iraq, it is implied, will be subjected to what Pentagon planners call "total spectrum warfare", which employs multiple tactics. 

This strategy is intended to prevent President Saddam firing his missiles, possibly with chemical and biological warheads, at Israel. It will also provide the attacking US-led coalition with forward bases to attack the central stronghold of the regime and bypass a reluctant Saudi Arabia as well as Jordan and, possibly, Turkey. 

No problems are likely in the predominantly Kurdish north, which is already largely autonomous and protected by a no-fly zone policed by US and British war planes. Much the same goes for the south, populated by Shia Muslims with a long history of resistance to President Saddam. 

According to the Post, American troops from the 101st Airforce Division and comparable British units would move into northern Iraq, also to prevent President Saddam's forces retreating there. The plan calls for US marines and British forces to seize airstrips around the port of Basra in the south. Of the total allied forces deployed, "several thousand" would be British, the only non-US contribution on the ground. 

The initial attack would be accompanied by intense psychological "psyops", measures to incite Iraqi commanders to defect and to assure civilians that the war is not directed at them. "The patriotic thing for generals is not to carry out orders of Saddam Hussein," Condoleezza Rice, George Bush's National Security Adviser, told ABC news yesterday. It was also important, she added, "to send the message to the Iraqi people that they deserve better". 

Pentagon planners reckon that President Saddam might be toppled by a coup. If not he might face a multi-pronged armoured attack from the north, south and west towards Baghdad. If the resistance continues, the Bush administration's nightmare could materialise – street-by-street fighting for the Iraqi capital, in which heavy civilian casualties would be almost inevitable. For that purpose, the biggest force available is said to be between 200,000 and 250,000 men, roughly half the size of the force assembled to drive Iraq from Kuwait 11 years ago. 

General Tommy Franks, the head of US Central Command, and his military colleagues have prevailed over civilian officials who believed that a less orthodox "inside out'' war, which struck the regime at its heart at the outset, could do the job just as well with much smaller forces. "This is a classic Army/Tommy Franks plan. It's their game plan,'' a former general said. 

The idea is for the attack to merge into a military occupation of part of the country, from which to distribute food and other aid to civilians.