The high price of holding Helmand

The death in action of the commanding officer of the Welsh Guards is a great sadness to his family, friends and his community in the regiment and the army. But it can hardly be deemed the "devastating blow" to British operations in Helmand portrayed by the BBC – nor even the "huge blow" described by the Times on Friday.

"This what brave and capable officers do," a senior general told me this morning. "They lead their men in the best way they can, and this often means putting themselves in harm's way. It is part of the job."

By all accounts, Lieutenant Colonel Rupert Thorneloe, 39, was an outstanding officer. His legacy is in the battalion he trained and took to the fight in the Helmand valley where he died on 1 July – the great British military anniversary. On the same day 93 years ago, just shy of 20,000 of its sons were killed in a few hours on the first day of the long Somme offensive.

The Welsh Guards have been involved in some pretty hard pounding in Helmand, and still are. In just over two months, they have lost their commanding officer, a company commander, a platoon commander and a senior lance sergeant. Out of the 30 men in the reconnaissance Platoon, 19 have sustained injuries in combat. A brilliant insight into the nature of the fighting and the two big British and American operations along the Helmand river is given by Tom Coghlan in the Times.

On hearing of the colonel's death, Coghlan said the guardsmen just carried on with the business in hand. This is exactly what happened when the last British commander was killed in battle. As it happens, I was some 300m back from where Lt Col H Jones of 2nd Battalion the Parachute Regiment was killed in the battle at Goose Green in 1982. The battle had stalled when he died, and after a brief rearrangement of who was in charge, Major Chris Keeble went forward, made adjustments to the plans in consultation with the company commanders and, slowly and surely, the paratroopers regained the initiative.

I do not recall anyone in the battalion talking about "a devastating blow" that afternoon on the Darwin Isthmus in the Falklands – they had too much work to do. H Jones gave orders about what should happen if he should be killed: the battery commander would direct the immediate battle, until the second-in-command, Major Keeble, could come forward to command the whole battle. Colonel Thorneloe will have made the same provision, with his second-in-command now in charge.

But this doesn't mean that aren't some serious tactical and strategic issues raised by his death. First, there is the proven vulnerability of the Viking tracked vehicle, which is too thinly armoured to resist the new booby trap bombs of the Taliban. Last month, the Oxford coroner welcomed the army's announcement that the vehicles – originally designed to move ski troops in the Arctic – are to be replaced.

The most worrying aspect is the simplicity of such bombs used by the Taliban. The bombs are buried in the dirt and sand with very little in the way of electronics and only pressure plates to set them off when a vehicle trundles over or near them. This makes them very hard to detect by mine clearance teams.

The strategic question is raised by the big operations involving up to 10,000 British, American and Afghan troops now under way. The aim is to clear the Taliban out of the villages along the river, the prime poppy-growing territory, so they can hold relatively trouble-free national elections for the presidency and the assembly on 20 August.

The aim is described as "pushing back" the Taliban. No one is talking of an outright defeat of the Taliban across southern Afghanistan. Soon, the international forces will have close to the numbers the Russians had the height of their occupation and war against the Mujahideen in the 1980s – some 110,000 troops on the ground.

Unlike that war, the fighting has spread well beyond Afghanistan itself, into the North West Frontier territories and the Swat valley of Pakistan, and is now part of a broad regional conflict. Russia's entanglement in Afghanistan ran for a disastrous decade and ended in a withdrawal that could only be called defeat; today, the commander-in-chief of the most powerful international force contingent, President Obama, has given himself a deadline of two years to get this, the military, phase of the job done.