The strain being placed on the Army has been highlighted by the unique creation of a brigade for a one-off tour of duty to fight the Taleban.

The new 11 Light Brigade, which will take over from 19 Light Brigade in October, has been formed out of a mix-and-match of half a dozen regiments, including the 1st Battalion Grenadier Guards, the 2nd Battalion The Yorkshire Regiment, 1st Battalion The Royal Welsh Regiment, 3rd Battalion The Rifles, The Household Cavalry Regiment and 10 Queen’s Own Gurkha Logistic Regiment.

The Ministry of Defence said it would be commanded by Brigadier James Cowan and consist of about 8,300 troops — 700 fewer than the present British force in Helmand province — “unless Gordon Brown agrees to maintain the 9,000 level”. It will be disbanded in April and the troops returned to their previous formations.

The Prime Minister announced in April that the extra 700 soldiers sent to Helmand would only stay for four months, during the Afghan election period, and would be withdrawn in October.

In 2007 52 Infantry Brigade, which was converted from a Scottish Territorial Army formation into a regular unit for Afghanistan, was sent to Helmand in October 2007. This brigade was not disbanded however after its tour of duty.

The old 11th Infantry Brigade served in both world wars and was involved at Dunkirk in 1940 and in the British-American invasion of northwest Africa in 1942. It was deactivated in 1958.

Soldiers are supposed to have a two-year gap between missions overseas. With simultaneous operations in Iraq and Afghanistan, however, the Army has not had enough brigades to maintain the cycle. Now that the Iraq mission has been reduced, there should be more brigades available to serve in Afghanistan.

Ideally, the Army needs ten light brigades to maintain its operational cycle without requiring soldiers to serve overseas every 12-18 months.The 4 Mechanised Brigade, which has served in Iraq, will be sent to Afghanistan after 11 Light Brigade. Major-General Nick Carter, General Officer Commanding 6 Division, will take his headquarters to run the regional command which covers the four provinces in southern Afghanistan, including Helmand where most of the British troops are located. He is taking over from a Dutch general.

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