LONDON — BY deciding to strengthen their commitment to Operation Desert Shield with substantial numbers of tanks and strike aircraft, Britain and France have confirmed that any American-led military campaign against Iraq will be fought along lines never before attempted. Defense experts say the British and French forces preparing to depart were designed and trained to fight an air-land battle in which an effort would be made to saturate Iraqi defenses with attacks over the entire depth of the battlefield.
This is a style of warfare for which Western troops in Europe have been trained but which they have never used.
Last Friday, Tom King, the British defense secretary, ordered to Saudi Arabia the Seventh Armored Brigade, consisting of up to 8,000 men and 120 tanks, with additional air support. The next day, angered by Iraqi troops' forced entry into the French Embassy in Kuwait, President Fran,cois Mitterrand offered to send 4,000 men equipped with 48 tanks and supporting aircraft to the Gulf if Saudi Arabia agreed.
Egypt is sending 15,000 more troops to Saudi Arabia to join the 5,000 soldiers and paratroops already there, defense sources said yesterday. Diplomats said Syria, which has sent 4,000 troops, pledged to send as many as 11,000 more soldiers and 300 tanks.
When these forces are added to the American formations already in Saudi Arabia or on their way, defense analysts say, Iraqi President Saddam Hussein will confront a formidable combination of land and air power, backed up by the many warships already assembled in the Gulf region.
Before Britain and France announced large increases in their contribution to Desert Shield, there had been strong United States congressional criticism of Europe's level of support.
There are other views on what a campaign would be like. One British official says: ``Much would depend on how quickly Iraq's opponents could establish mastery of the battlefield. It would be necessary to gain control in two or three days, otherwise everybody would get bogged down and there might be no victor.''
John Keegan, a leading British military analyst, says the kind of war now likely to be fought against Iraq would depend on a wide range of carefully coordinated actions.
``Enemy armor would be attacked by tanks and missile-firing helicopters as well as by artillery firing cluster weapons and multiple-launch rockets,'' he said.
Iraqi command centers would be targeted by guided weapons. Iraqi signals systems would be blacked out by electronic countermeasures, with lines of supply disrupted by deep air strikes.
The combination of weapons and equipment now being planned for deployment in the Gulf, Mr. Keegan says, would enable an American-led force to use ``a complex of weapon systems'' - ground and airborne, short-range and long-range, metal and electronic.
This interpretation of the type of campaign being contemplated is confirmed by the ``mix'' of weapons Britain is sending to the Gulf. In the largest deployment of British armor since World War II, the government has ordered up 120 Challenger tanks, an infantry battalion equipped with Warrior armored fighting vehicles, an armored reconnaissance squadron, a field artillery regiment with 155-mm self-propelled guns, an air defense battery with Javelin missiles, and a wide range of supporting services.
In Washington, Gen. Michael Dugan, the US Air Force chief of staff, said military air power was the only effective option to force Iraqi troops from Kuwait if war erupted. Strikes might include a massive bombing campaign against Baghdad that would specifically target Saddam, he told the Washington Post.
It will be weeks before the entire Desert Shield force is in place and ready for action. A British government source said this weekend that the first half of November was the soonest a fully coordinated allied military air-land operation might occur.
In Washington yesterday, it was reported that less than a third of the US Army's heavy commitment had arrived in Saudi Arabia.