A "radical" shift is needed in defence spending to prioritise the number of troops working on the ground to win over hearts and minds, the head of the army said last tonight.
General Sir David Richards told an audience in central London that the UK was lagging behind its enemies in being prepared for modern warfare.
Current and future conflicts would focus on using communication to drum up support and would need more British troops to work among populations such as that in Afghanistan, he said.
In a speech at the International Institute for Strategic Studies, General Richards said there was too much emphasis on "hugely expensive" cutting-edge equipment in the military.
Instead the focus should be shifted to providing more troops and staff, which would be cheaper.
He said: "If one equips more for this type of conflict while significantly reducing investment in higher-end war-fighting capability, suddenly one can buy an impressive amount of 'kit'."
Gen Richards went on: "Future wars of mass manoeuvre are more likely to be fought through the minds of millions of people looking at computer and television screens than on some modern equivalent of the Cold War's North German Plain. Indeed some might argue the screen is our generation's North German Plain, the place where future wars will be won or lost."
He said the Government must take the risk of changing its defence priorities or "run the far greater one of trying with inadequate resources to be all things to all conflicts and failing to succeed in any".
Getting the right number of skilled people "must not be viewed as an overhead" but a "precious capability that has to be paid for", he said,
A balance should be struck between Britain's ability to fight a traditional war and the new kind of conflict.
"This is about ensuring a balance across all three (services) and with allies, between our ability to fight a traditional war of air, maritime and ground kinetic manoeuvre and being able to conduct a far more difficult one amongst and with and for the people," the former International Security Assistance Force (ISAF) commander said.
He said the UK's armed forces were equipped for an outdated form of warfare and this must change.
Gen Richards said: "Our armed forces are primarily structured and equipped for the last war, for a war of technology against technology, armour against armour. We have pared down our forces numbers, replacing people with hardware and thoughts with process.
"Yet as the war of the present and the future is for the people, for their understanding and loyalty, we must be capable of being among them.
"This has a radical consequence for defence. It requires mass."
The head of the Army admitted that this could "come up against resistance from those who control the purse strings".
A review of the country's defence policy is being carried out and the initial proposals are due to be published in a Green Paper early this year.