When will British troops come home?

That is the question British troops are asking as they fight in Afghanistan and Iraq. So is there any chance the wars will be over by next Christmas?

What are our troops doing in Afghanistan and Iraq? Are they fighting a "war on terror"? If, indeed, there is such a thing, isn't it being conducted here in Britain, where the 7/7 bombings took place nearly 18 months ago, where other would-be bombers have been jailed, and where we are still undergoing additional safety precautions at airports because of last summer's alleged plot to blow up transatlantic airliners?

British soldiers in Basra or Camp Bastion in Helmand Province do not have much time to debate such abstractions this New Year's Eve, however. All they know is that they are in the midst of conflicts which are not only growing increasingly dangerous, but are rapidly coming to resemble each other. The only question that preoccupies them is: "When can we go home?"

During 2006 the consequences of neglecting Afghanistan to launch an invasion of Iraq became evident, but in Iraq this was the year the country sank unquestionably into civil war. The year began and ended with the fallout from two elections, the first in Iraq itself, the second in the US. The former was presented as yet another in a series of supposed "turning points" which would at last put Iraqis on the path to stability and democracy, but the latter was the pivotal event: the Democratic victory in the mid-terms marked the moment when the American electorate finally rejected President George Bush's heedless denial of reality in Iraq.

As 2006 began, British troops in southern Iraq, already largely confined to their bases by a series of roadside bombings and suicide attacks the previous autumn, were cautiously hoping that the election held shortly before the new year might signal a way out. But that was always going to depend on events further north, where American forces had a worsening Sunni insurgency on their hands. And, as the politicians wrangled on and the number of British deaths in Iraq reached 100 - it now stands at 127 - the conflict turned inexorably into civil war.

The key event was the bombing of the Askariya shrine in Samarra, the holiest in Shia Islam, on 22 February. Not only was its famous golden dome severely damaged, more than 1,000 people were killed in ferocious sectarian attacks between Shias and Sunnis in ensuing days. So many atrocities have followed that the bloodshed has become almost routine; it now requires more than 100 deaths in a day to excite much notice.

The rising tide of slaughter has swamped all the supposed tokens of progress, such as the final creation of a government in April under Nouri al-Maliki, or the air strike in June which killed Abu Musab al-Zarqawi, the brutal head of al-Qa'ida in Iraq, or the verdict on Saddam Hussein. The timing of his death sentence in early November was clearly aimed - unsuccessfully, as it turned out - at influencing the mid-terms. Saddam was duly executed at dawn yesterday, but only the deluded imagine that it will do anything to stop Iraq being pulled apart.

And all the time American troops are being lost at an accelerating rate: some time around the New Year, the total will reach 3,000, fuelling the disillusionment with Iraq that now prevails in America. A stream of reports by think-tanks and assessments by commanders during 2006 made it clear that the Iraqi government is not only incapable of controlling the killing, but is responsible for much of it; that reconstruction is at a standstill, leaving Iraqis worse off than they were under Saddam; and that the hope of training enough Iraqi security forces to hand over responsibility to them is an ever-receding mirage. This was articulated by the report of the Iraq Study Group (ISG), of which The New Yorker commented: "That Bush's war in Iraq is an unmitigated catastrophe has been known for some time. What the Iraq Study Group has done is to make it official."

So what will happen in 2007? Mr Bush and his advisers were spending the festive season considering their strategy, but they remain a coterie in denial. Already the President has dismissed many of the ISG's findings, such as the need to draw Syria and Iran into the search for a solution in Iraq. The White House may well support the idea, put forward by Senator John McCain, among others, that troop numbers in Iraq should be temporarily raised to regain some measure of control. Although many military chiefs are strongly opposed, the new operational commander in Iraq, Lieutenant-General Raymond Odierno, is a supporter: since many blame his "search and destroy" tactics for inflaming the insurgency, an increase in troops could well see an upsurge in bloodshed.

If that fails, the temptation will be strong to put the blame on the Iraqis, and on the hapless Mr Maliki in particular. The Americans could seek to oust him, but no prospective replacement is likely to achieve what the US wants, which is to exclude the most radical Shia militia, the Mehdi Army, and its fiery leader, Moqtada al-Sadr, from power so that co-operation can be sought with "moderate" elements of the Sunni insurgency.

None of this bodes well for the ordinary British soldier in southern Iraq, where their presence is exacerbating the security situation. They should leave "soon", according to the head of the army, General Sir Richard Dannatt. The dramatic demolition of a Basra police station on Christmas Day should be seen in this context - it is a last attempt to weed out "rogue elements" in the local police force so that a significant reduction in British forces can be made early in 2007.

There are already detailed plans to close and consolidate bases in and around Basra, and bring some 3,000 troops home, out of a complement of around 7,200. The question is whether General Dannatt's political superiors will agree, and that in turn may depend on how such a withdrawal would be seen in Washington, where no early escape from the quagmire of Iraq can be envisaged. But Tony Blair, who marched side by side with George Bush into disaster, is departing, and his successor may want to show less concern for what the US thinks.

It has become clear over the past year that, having broken the terrorists' grip on Afghanistan in 2001, the US and Britain gave them a new haven and fresh inspiration in Iraq. Now, more than five years on, Iraq's anarchy is reinfecting a weakened Afghanistan, and British forces are at the centre of the struggle to save the patient.

A half-forgotten conflict returned to public consciousness here as 4,000 British troops were deployed to the southern province of Helmand, not only a Taliban stronghold but the source of half the heroin on British streets. Almost immediately, however, their stated mission - to support reconstruction efforts, hopefully "without firing a shot", in the words of the then Defence Secretary, John Reid - turned out to be far bloodier than anyone had been led to expect.

Over the objections of many commanders, who said it was never part of the original brief, small forces were sent into lawless towns in northern Helmand, and promptly found themselves fighting for their lives. Reconstruction was largely put aside as 16 Air Assault Brigade battled the Taliban over the summer, inflicting heavy damage on the insurgents at the cost of 16 British lives. With the death of a Royal Marine last week, losses in Helmand this year have since risen to 20, but other parts of the south have seen equally heavy fighting, with Canadian forces in neighbouring Kandahar province suffering a similar number of deaths.

The resurgence of the Taliban has made 2006 the most violent year in Afghanistan since 2001. Lieutenant-General David Richards, the British commander of Nato forces in the country, which took over from the US, hoped to win Afghan support with a more flexible form of soldiering, in contrast to the American use of overwhelming force. But lack of numbers has obliged Nato to employ similarly heavy-handed tactics, to the despair of President Hamid Karzai, who sees the already fragile legitimacy of his government being eroded as civilian casualties mount.

As 2007 begins, the prospects are clouded. Nato is aiming to win over the Afghan populace during the winter lull in fighting with "quick impact" aid projects, such as refurbishing schools, but the Taliban is rapidly adopting insurgency tactics developed in Iraq. Suicide bombing, once rare, is taking a growing toll, both of Nato troops and Afghan civilians, and roadside bombs are both more frequent and more sophisticated, again thanks to the influence of Iraq.

Earnings from Helmand's record opium crop in 2006 are helping to fund the Taliban, and any move to crack down on the province's poppy growers before the next harvest in May is likely to embroil British troops in all-out confrontation with an alliance of insurgents, drug lords and farmers deprived of their living.

The new intensity of fighting in southern Afghanistan is already undermining stability in the whole of the country, and there is a clear risk of Nato forces becoming locked into a vicious circle of "no development without security, no security without development". To break out of it, any British troops withdrawn from Iraq are likely to be needed in Afghanistan.

Lt-Gen Richards is within days of stepping down. He is to be replaced by an American commander who, like his counterpart in Iraq, believes in far more aggressive tactics. If Afghanistan is treated with the same careless arrogance as Iraq, it would not be long before it descends into equal chaos, and this time British troops would be intimately involved, unlike in Iraq, where they are relative bystanders. It is possible to envisage a draw-down of British forces in Iraq during the coming year, but the mission in Afghanistan is likely to last well beyond the three-year timeframe announced by Mr Reid last January.

What any of this has to do with the "war on terror" declared in 2001 is unclear, but war it certainly is, in Afghanistan as well as Iraq. And there is no chance of any halt to hostilities in 2007.

THE NEXT MOVE

Tony Blair Enters his last year in office under pressure to agree to a substantial reduction of British troops in Iraq early in 2007, especially if things get hotter in Afghanistan. The US could oppose an Iraq draw-down, but that may be of less concern to Mr Blair's successor.

George Bush Expected to announce a new Iraq strategy soon, in the wake of the Iraq Study Group report and a series of conclaves with his advisers. The big question is whether he will heed calls for a temporary increase in US troops, in an attempt to reassert control.

Nouri Al-Maliki Installed as Iraqi Prime Minister after the US refused to endorse a candidate associated with the main Shia militia. But the Americans may well seek to oust him in 2007, casting him as the scapegoat for failing to stem the bloodshed caused by the militias.

Lt-Gen Raymond Odierno The new operational commander in Iraq supports a "surge" in US troop levels in 2007, but his aggressive methods when he commanded forces in Sunni-dominated areas of the country in 2003 and 2004 are blamed by many for fuelling the insurgency.

Hamid Karzai The Afghan President, elected in 2004, has seen optimism evaporate amid a resurgence by the Taliban during 2006. He has complained that increasing civilian casualties in the war against the insurgents are damaging support for the presence of Western troops.

Lt-Gen David Richards The British commander of Nato forces in Afghanistan now controls foreign forces in all areas of the country, but the US disagrees with his efforts to restrain the use of force against the insurgency. Due to be replaced early in 2007 by a more "gung-ho" American.