The Government launched a shake-up of defence policy yesterday to combat terrorist attacks, but faced objections from senior military officers over one of the main proposals.
Geoff Hoon, the Secretary of State for Defence, is considering the use of the Territorial Army to guard strategic locations. But senior officers feel this would be an unsuitable task for the part-time soldiers and might result in many leaving the force.
Many more resources allocated to homeland defence, and the deployment of British forces abroad for a series of wars against attrition are the central tenets of the new thinking.
Air defences against attacks such as those against the US World Trade Centre had been strengthened, the Ministry of Defence (MoD) revealed, and RAF warplanes had been scrambled a number of times to check out suspect aircraft.
With the probability of more missions abroad for the armed forces, and light mobile brigades likely to use hi-tech weaponry, Mr Hoon believes the 40,000 TA personnel should have a much greater role in internal defence.
He said: "I can see a role for reassuring people, at least in times of national emergency, and for key installations to be guarded. It may well be there is a role there for reservists in fulfilling those important responsibilities.
"The events of 11 September, and the challenge they pose for ... homeland defence, is something we need to consider carefully. One of the important questions is whether we want to use regular members of the armed forces for that purpose, particularly when they are so extensively engaged overseas."
But a senior defence source said: "It is not the ethos of the Territorial Army to carry out static guard duties at places like Heathrow and Sellafield. People join the TA to go to exciting places and do exciting things. There is a danger that we may lose people if they end up doing such static duties."
Senior officers think instead that the TA personnel should be employed more in fields such as communications and intelligence gathering, as well as in service abroad.
The second part of the Government's proposals – that Britain must be prepared to carry the war to terrorists abroad – also led to concern. Critics pointed out that British forces were already suffering from severe "overstretch" after a series of deployments in Kosovo, Sierra Leone, Macedonia and Afghanistan.
Introducing the consultation document, The Strategic Defence Review: A New Chapter, Mr Hoon said Britain had little choice in the matter and that defence was as crucial as health and education.
Mr Hoon declared that the armed forces must mount "find-and-strike" operations abroad, and said their scope had to be extended beyond Europe and the Middle East, which formed the basis of the 1998 Strategic Defence Review.
"The military capability on which we spend the defence budget is not an optional extra. It is absolutely essential to our part in maintaining international security," the Defence Secretary told the Commons. "We need to put more emphasis on being pro-active and, where possible and justifiable, pre-empting problems rather than simply waiting for problems to come to us."
Senior MoD sources said there would be much more emphasis placed on hi-tech weaponry to strike terrorist groups and the "rogue states" harbouring them.