As U.S. Marine Corps Maj. Gen. Richard Mills takes over command of Helmand - Afghanistan's most violent province -- from the British this week, Britain's Conservative-led government of David Cameron is busy in London wrestling with the question: just what has been going wrong?

The shake-up of NATO command structures in Afghanistan -- which spins off a new divisional headquarters, Regional Command South West -- from the British-led Regional Command South in Kandahar, now places almost all of Britain's combat troops in Afghanistan rather uneasily under the leadership of an American.

With a force now of nearly 10,000, the Brits have been fighting in Helmand since the summer of 2006 and lost more than 290 troops. While it is perilous to consider the province's woes in isolation from the entire country's downward spiral, there is a need to ask why things have gone particularly badly in Helmand.

For the British, it is a matter of national reputation. Not is only is there a small matter of the British Empire's three previous Afghan wars thought (wrongly, as it happens) to have been disastrous failures. There is also the widespread view, shared by a majority of the British Army itself, that the U.K. tarnished its reputation for counterinsurgency operations by getting wrong its campaign in Basra, Iraq, and requiring an embarrassing bail-out by the Americans in Operation Charge of the Knights in 2008.

Is Helmand another case of waiting for the Yanks to come?

As Prime Minister David Cameron attempts a review of the strategy, among the first to face the music are the most senior officers. On Sunday it emerged that the chief of the defense staff, an RAF man, Air Chief Marshal Sir Jock Stirrup, is to be axed, presumably in favor of a man in khaki. The most obvious candidate is General Sir David Richards, a former NATO commander in Afghanistan, and currently head of the Army.

As painfully described in an investigation published last week by the Times of London, the charge against military top brass, and those like Stirrup who talked endlessly of constant progress on the ground, is of filtering complaints from field commanders and junior soldiers so that politicians under the previous Labour administration got spared the full picture of how badly things were going in Helmand and the many shortfalls, for example, of war-winning military equipment and in basic welfare for the troops and their injured. Britain went into Helmand, the article described, with its "eyes shut and fingers crossed."

Adam Holloway, a former Guards officer and now backbench Tory MP, added in the Sunday Times: "There was a tendency under the Labour government to promote ‘politicians in uniform' rather than officers willing to give frank advice about the strategic drift in Afghanistan."

As Holloway implies, some of the criticism of senior commanders like Stirrup for failing to "back our boys," rather misses the point. While the insufficiency of resources like helicopters, bomb technicians, and mine-protected vehicles was arguably a betrayal of the "military covenant" that a nation owes an armed forces bearing so much sacrifice, none of these deficiencies go far to explaining why the war has been going so badly.

So what did go wrong with British leadership in Helmand? What part did the U.K. play in the transformation of what was a quiet backwater of the country in 2006 into this violent quagmire which now requires a garrison of 20,000 foreign troops (twice what the Soviets deployed to the province)?

The British had deployed in 2006 with an original plan for Helmand that echoed key elements of what was to become Gen. Stanley McChrystal's strategy. Its mission was to avoid combat and concentrate on protecting the population by providing basic security and fostering development in a narrow zone of central Helmand.

But the plan was not followed. As rebellion spread, the force of 3,300 personnel, representing an initial combat strength at first of little more nine platoons, were scattered across the district centers of northern Helmand. Pinned down in small Alamo-style outposts, their presence served as a magnet for the Taliban and an inspiration for general revolt. And, forced to defend themselves, they resorted to air strikes and heavy weapons that rubble-ized the centers of towns like Sangin and Musa Qala, and forced out the populations of Garmsir, Kajaki and Now Zad.

Now committed to defending a vast geographical area (and persuaded by President Karzai that any withdrawal would hand the Taliban a major victory), over successive years, Britain's Task Force Helmand tripled in size but, despite reinforcement by Danes, Estonians and American units, was always outstretched by the spreading rebellion. British troops and their Afghan partners have never been in sufficient strength in any one place to dominate the ground effectively and provide the kind of basic security required to implement the central elements of an effective counterinsurgency approach, like reform of local government or meaningful development work. While the U.K. trumpeted its "comprehensive approach" -- the unified application of both civil and military power -- the slogan was a parody of reality.

The population of Helmand is highly-dispersed, scattered among the compounds that dot the "Green Zone," as the irrigated land on either side of the Helmand River and its tributaries is called. While the British-led Task Force could cling on to the major towns like Sangin, Gereshk, and Lashkah Gah, real population security depended on securing the land that stretches between them.

Wedded at first to a conventional mindset, British operations initially sought to break the back of the Taliban revolt with endless and bloody "sweeps" up and down the Green Zone. The Taliban got suppressed for a few weeks or months and then came back. Troops came to refer to this disparagingly as "mowing the lawn."

The sweeps got followed by another approach of "ribbon security" -- an aspiration of constructing a chain of Forward Operating Bases up and down the Green Zone to provide a more extensive enduring presence -- up the Helmand from Gereshk to Sangin and then ultimately upstream as far as the strategic hydroelectric dam at Kajaki.

The approach was flawed. There were never enough troops for such ambition. And the overstretch got worse by the fall of 2008, when the revolt started spreading to previously relatively-quiet central Helmand and the gates of the provincial capital, Lashkah Gah. In the assaults that began in July 2009, the British drained resources from Sangin and pushed troops into the central Babaji and Malgir districts west of Lashkah Gah. They were joined now by U.S. Marines who took over Garmsir, Nawa, and the southern Helmand district of Khan Neshin. The U.S. Marine presence has been expanding ever since, leading to today's change-of-command.

Foreign interventions like the Iraq and Afghan campaigns have proved Donald Rumsfeld's truism that you "go to war with the Army that you have." Whatever the mistakes made in the early days, success depends on the speed and wisdom with which you assess and then adapt.

The charge then against British commanders is that despite the sacrifice and heroism of their troops, they failed to alter their strategy and their people fast both from conventional war to counterinsurgency; and secondly to a more nuanced approach that tailored activity to the finite resources available. Constrained by political demands to portray an ever-rosy but false picture of relentless progress, they were condemned to what retired former Helmand commander, Maj. Gen. Andrew Mackay, has called "an endless muddling through."

For all that, as a counterinsurgency campaign, the war in Afghanistan is yet young. For U.S. commanders, there is little cause for smugness. If the British in 2006 arrived with a conventional mindset, they were confronting an insurgency already set aflame by a then hyper-conventional U.S. command and a U.S. political alliance with drug barons and unpopular corrupt warlords, all in the name of counterterrorism.

And if the principal cause of British failure has been the routine of taking a given resource and spreading it as thinly as possible to the point of being ineffective, then the U.S. surge shows signs of adopting the identical rule-of-thumb. As battalions dig in across the country in new towns and villages, it has to be asked if the offensive comes way ahead of a meaningful plan to make their inevitable sacrifice worthwhile.

As General McChrystal has made plain, the key is to adapt to an approach geared to the roots of rebellion and the security of the population. As my recent experience on the ground indicates, putting all that into practice is proving as difficult now for American troops as their British cousins.

The forgotten conclusion from their early defeats in the Afghan wars drawn by a few wise minds in the British Empire administration was that, in a complex cultural environment like Afghanistan, about which they had to admit they knew very little, sometimes "masterful inactivity" was a better option than gallantly intervening and making things worse.

Stephen Grey is the author of Operation Snakebite: The Explosive True Story of an Afghan Desert Siege (Viking Penguin, 2009), and a foreign correspondent for the Sunday Times of London. He will be speaking at the New America Foundation on Wednesday June 23 at 4:00pm; details and RSVP here.