The broken back of the British army.

The peacetime maintenance of military and naval forces by a country has little to do with sustained war-fighting. That reality seems to have been lost on the current crop of political leaders from George W. Bush through Britain's Tony Blair and extends to Canada's Stephen Harper.

None of them understand that once a fixed-asset, manning-capped military force is committed to combat it will begin to wear out. Unless it is constantly replenished, with both equipment and personnel, it will eventually collapse. The Rumsfeld doctrine of "More technology; fewer troops" has been proven a failure. If a country's military is committed to war, intent on complete victory, it needs to begin expanding its ranks immediately and the industrial sector of that country needs to be commandeered to such a degree that a constant flow of materiel and equipment is being made available to the expanding military body.

Bush and Blair didn't do that. They went to war, confident that they were technologically superior to their enemies, with their peacetime military services. And, while the Pentagon continues to proclaim the US armed forces' health in both personnel and equipment, the British are telling a different story.

Gen Sir Richard Dannatt has told senior commanders that reinforcements for emergencies or for operations in Iraq or Afghanistan are "now almost non-existent".

In the memorandum to fellow defence leaders, the Chief of the General Staff (CGS) confessed that "we now have almost no capability to react to the unexpected". The "undermanned" Army now has all its units committed to either training for war in Iraq and Afghanistan, on leave or on operations.

One of the primary reasons for keeping a peacetime army is to maintain a national ability to react quickly to unexpected situations and provide a cadre of professionals able to build a larger force. It is a "force in being" intended to provide a visible demonstration of a nation's resolve to defend itself. In modern times, it is a contingency force able to operate within a specific set of limits. Given the expense of maintaining and equipping armed forces, most governments keep the absolute minimum necessary to deal with short term emergencies and, if to be committed to combat, expeditions of limited duration.

There is just one battalion of 500 troops, called the Spearhead Lead Element, available to be used in an emergency, such as a major domestic terrorist attack or a rapid deployment overseas.

One battalion. Britain is, quite literally, defenceless.

Britain's retaking of the Falkland Islands in 1982 underscores the limits imposed on peacetime armed forces. Britain committed a huge portion of its armed forces to the Falklands War. Had the Cold War with the Soviet Union not been in full swing at that time, there is a distinct possibility that Britain might not have been able to pull it off. NATO headquarters got a bad case of nerves when Margaret Thatcher tossed the 28,000 of Britain's armed forces into the South Atlantic expedition.

What is rarely discussed however, is that Britain was on the brink of losing. Had the Argentinian forces managed to hold out for another week the British would likely have had to withdraw. Having been fully engaged for three months, casualties had weakened the British forces, equipment was desperately in need of static maintenance and, food and ammunition were at critically low levels. When the Argentinians surrendered on 15 June, 1982 the British had suffered 258 personnel killed and 777 wounded. 34 British aircraft were lost and the navy had lost 2 destroyers, 2 frigates, 1 landing ship, 1 landing craft and 1 large container ship. Additionally, there was extensive damage to several surviving warships, serviceable aircraft were becoming maintenance nightmares and ground vehicles were in desperate need of parts and repair.

The whole thing had lasted 74 days, including the 8000 mile transit of the British task force. While Britain emerged victorious, it placed enormous strain on the armed forces and a long period of rebuilding had to be undertaken.

The current crop of conflicts has been going on for over five years. The British government had expected that involvement in Afghanistan and Iraq would steadily decline after initial military victories. However, the Bush administration, distracted by the desire to topple Saddam in Iraq, failed to complete the job in Afghanistan and did not consolidate the mission. Iraq, indisputably a war of choice on the part of the US and Britain, has degenerated into a war of proportions neither government had examined as a possibility. Both Afghanistan and Iraq are now faced with wars of "resistance".

The document said that Britain's second back-up unit, called the Airborne Task Force formed around the Parachute Regiment, was unavailable. It was unable to fully deploy "due to shortages in manpower, equipment and stocks".

Most of the Paras' vehicles and weapons have stayed in Afghanistan with other units using them in intense battles against the Taliban.

Parachute Regiment officers are deeply concerned that with nearly all their equipment abroad they are unable to train properly for future operations.

The Paras also no longer have the ability to parachute as a 600-strong battalion because no RAF planes were available to drop then en-masse, the document said. The situation was unlikely to be resolved until late August.

With the Army significantly under-strength by 3,500 troops – many disillusioned with being constantly on dangerous operations and away from their families – it is now struggling to plug the gaps on the frontline.

"The enduring nature and scale of current operations continues to stretch people," Gen Dannatt wrote.

The Army now needed to "augment" 2,500 troops from other units onto operations in Iraq and Afghanistan to bring up the total force to 13,000 required. This remained "far higher than we ever assumed," the CGS said.

"When this is combined with the effects of under-manning (principally in the infantry and Royal Artillery) and the pace of training support needed to prepare units for operations, the tempo of life in the Field Army is intense."

The Army has also been forced to call up almost 1,000 Territorial Army soldiers for overseas operations. The general's concerns came after three RAF personnel were killed in a mortar or rocket attack on the main British headquarters five miles outside Basra bringing the total dead in Iraq to 162.

With the main force pulling out of Basra city to the air station in the coming months there is concern of increased attacks on the large base where some troops are forced to live in tented accommodation.

A lack of vehicles meant that "training is significantly constrained".

Gen Dannatt was also "concerned" that some equipment, particularly Scimitar light tanks that are vital to fighting in Afghanistan but are 40 years old, "may be at the edge of their sustainability".

More needed to be done on housing and pay in order to retained troops because "people are more likely to stay if we look after them properly".

The pressure on numbers was partially being alleviated by bringing in civilian firms to train soldiers and guard bases and by "adopting a pragmatic approach to risk where possible".

While the current situation was "manageable" Gen Dannatt was "very concerned about the longer term implications of the impact of this level of operations on our people, equipment and future operational capability".

It is not the first time Gen Dannatt has raised concerns on Britain's fighting ability. A few weeks into his job last year, Sir Richard said the military was "running hot" and urged for a national debate on defence.

The plain-speaking officer later suggested that the British presence in Iraq was "exacerbating the security problems" and warned that the Army would "break" if it was kept there too long.

Gen Dannatt, who said manning was "critical" in the Army, called for extra infantry units earlier this month following the devastating cuts inflicted by his predecessor Gen Sir Mike Jackson which saw four battalions axed.

"General Dannatt's appraisal means that we are unable to intervene if there is an emergency in Britain or elsewhere, that's self-evident," a senior officer said.

"But this is a direct result of the decision to go into Afghanistan on the assumption that Iraq would diminish simultaneously. We are now reaping the reward of that assumption."

If you don't take your gear home with you, you can't train with it. If you can't train with your gear, you're not ready to use it when you arrive in theatre. The training that is done is preparatory for rotation into Iraq or Afghanistan, not the broader scope of skills required by a field army. With manpower shortages comes a shortage of trainers. And the whole thing becomes a death spiral.

Britain's situation could actually have been understated by Dannatt. The US, UK and Canada are all using their territorial militias to augment expeditionary forces. That means that should a contingency operation be required, even a domestic one, there will be a lack of troops available. The US has already experienced the effects of their "missing" National Guard which, instead of being available for emergencies, has in effect become an active-service force which is being stretched beyond its reserve-status limits. If Britain is digging into its Territorial Army for troops the condition is critical.