Justin is researching a new history of the Middle East for Allen Lane.

It’s difficult to be a peacekeeping force when there’s no peace to keep. It’s difficult when the international community promises you 26,000 peacekeepers, then struggles to give you 10,000. It’s difficult to make much progress when the number of rebel movements involved in the conflict has risen from a handful to more than 30 in the space of two years. And it’s especially difficult to succeed when government militias take it upon themselves to start killing your peacekeepers.

These are the unenviable challenges facing Unamid, the joint United Nations-African Union force charged with bringing peace to Darfur. Created by UN Security Council Resolution 1769 a year ago, Unamid is somehow expected to end a conflict that has lasted almost as long as the Second World War, killed as many as 300,000, according to the UN (10,000 if you prefer the Sudanese government’s estimate), and displaced around 2.5m people, a third of Darfur’s population. Rarely have expectations and realistic possibilities been so ill-matched.

Under the leadership of Rodolphe Adada, former foreign minister of the Republic of Congo, and its Nigerian force commander General Martin Luther Agwai, Unamid is doing a manful job. I spent three months assisting the mission as a communications adviser this summer and saw at first hand the brave work being done in virtually impossible circumstances. With a force of only 10,000 and no armed helicopters it’s hard to protect six million people spread across an area the size of France. One of Unamid’s simplest yet most important tasks is conducting daily firewood patrols, during which peacekeepers escort Darfurian women gathering fuel to cook meals for their families. The patrols are needed to provide security to the women who are otherwise at the mercy of militiamen who rape them with impunity. Ask the Sudanese government about the use of rape as official policy and they’ll tell you it’s a Western invention unknown to Sudan.

Khartoum does a nice line in Doublespeak. On July 8, seven Unamid peacekeepers from Rwanda, Uganda and Ghana were killed in a vicious ambush, the mission’s worst loss of life in its six months. The attack bore the hallmarks of a well-organised Janjaweed attack. In New York, Jean-Marie Guehenno, the UN’s outgoing head of peacekeeping, pointed the finger at Khartoum. A couple of weeks later, Sudanese President Omar al-Bashir suddenly popped up in El Fasher, Darfur. “We want to send this message to the world: we are the people of peace, we want peace . . . we are the only ones who can achieve peace in Darfur,” he told the usual rent-a-mob gathering.More empty words, you might reasonably think. The assurances of Khartoum, which has spent the past five years denying a hand in the ethnic cleansing of Darfur, do not count for much. Yet for the first time in several years, there is real hope in the air and it has nothing to do with Unamid.

On July 14, Luis Moreno Ocampo, the International Criminal Court’s chief prosecutor, formally accused the Sudanese president of war crimes, crimes against humanity and genocide in Darfur. Although the announcement had been widely anticipated, it still stunned the political establishment.

Few doubt that Moreno Ocampo has blown a gust of fresh air into the suffocating world of Sudanese politics. Many commentators fear the decision will wreck any chances of peace, failing to note that there is no peace process to spoil. With his back to the wall, there is no accounting what Bashir might do, they argue, ignoring the fact that he has had carte blanche to do what he likes in Darfur since 2003. In fact, although it is early days, the fallout from the ICC’s landmark move towards the indictment of Bashir looks positive. A friend with access to the highest levels of the regime reports unprecedented conversations at the presidential palace.

“The government’s in meltdown,” he reports. “They just didn’t think it would ever happen. They can’t believe it. The four or five people who run Sudan are now saying to Bashir, look where your policies have got us. They’re telling him, you can go to your rallies and demonstrations, you can shake your fist and rattle your walking stick, but you shut the hell up.” And strange to say, Bashir has been unusually quiet. The men in khaki are said to be furious with him. When the Darfur-based rebel Justice and Equality Movement (JEM) launched a bold attack on Khartoum in May, the president initially refrained from using the heavily Darfurian army to defend the capital, preferring the supposedly more dependable state security agencies. JEM came closer than most realise to toppling the government until the army stepped in with tanks and the airforce.

Now a national cross-party committee has been created to address the Darfur issue and end the conflict. Bashir has suddenly rediscovered an interest in Darfur, promising security, schools, roads and water. Window-dressing while the ICC judges ponder Moreno Ocampo’s evidence? Quite possibly, but these are suddenly interesting times. “There’s going to be a real push now for peace,” my palace mole reports. “Bashir’s got nothing to lose.”

Far from emboldening the Sudanese president and destroying a peace process that doesn’t exist, in other words, the ICC’s potential indictment may have been the best news for Darfur in years. Sudan watchers wonder whether Khartoum will finally ditch the president, who came to power in a 1989 coup, noting that the regime dropped the Islamic ideologue Hassan al-Turabi in the late Nineties in a bid to end its international isolation. Turabi, they note, was a far more important figure to the ruling National Congress Party then than Bashir is today.

Unamid’s dangerous and daunting mission in Darfur will continue but the real chance for peace lies in Khartoum. If Bashir the alleged war criminal is unable or unwilling to take it, he may find his time in charge runs out sooner than he’d like.

We take it for granted that the state should have a monopoly on the use of violence. Previous generations, however, were more relaxed about private-sector involvement in the bloody business of war.

‘Persians, Greeks and Romans all relied on hired muscle, to the extent that the Persian victory over Egypt at the Battle of Pelusium in 525 BC saw both sides field armies largely consisting of Greek mercenaries,’ Stephen Armstrong writes in this breezy canter through the recent history of guns for hire.

For much of the Middle Ages, European battlefields were the playgrounds of condottieri, puffed-up mercenary captains such as Sir John Hawkwood and Sigismondo Malatesta hired by Italian city-states to wage war.

The tradition persisted into the 19th century. Many of the troops Wellington mustered at Waterloo in 1815 were mercenaries.

Armstrong kicks off his story with the mercenary renaissance of the 1960s and the story of dashing David Stirling, founder of the Special Air Service.

Had it not been for Stirling and the British Mercenary Organisation, royalist forces in Aden would likely have collapsed under the onslaught of Nasser’s invasion in 1962.

In 1967, having embarked on a profitable business connection with King Faisal of Saudi Arabia, Stirling founded Watchguard International, the world’s first private security company. The Brits have been well represented in private security ever since.

Fast-forward to the second Gulf War in 2003. Much of the battlefield was by now a privatised business.

KBR (Kellogg Brown and Root), formerly a subsidiary of the Halliburton corporation, provides everything from accommodation, laundry and linens to vehicle maintenance, military canteens and convoys.

Private-security companies, most of them British and American, mushroom to fill the sudden demand for convoy protection, bodyguarding and armoured taxi services. Some are good. Others, such as Custer Battles and Triple Canopy at the cowboy end of the market, are not.

By the end of Donald Rumsfeld’s tenure as Secretary of Defense in 2006, there were 100,000 contractors in Iraq, a ratio of one to one with American troops.

With 14,000 personnel in uniform in early 2008, the British security company Erinys has more men in Iraq than the British Army. The work is dangerous, but the money is good.

From an Iraqi perspective, the arrival of large numbers of pumped-up young men with goatee beards who look as though they are dressed for a paramilitary catwalk, has been an unwelcome development.

Armstrong quotes an eyewitness describing the deployment of a security team from Blackwater, the American company awarded a $27.7 million no-bid contract to provide security for the American viceroy Paul Bremer.

‘The guards were chiselled like bodybuilders and wore tacky, wraparound sunglasses. Many wore goatees and dressed in all-khaki uniform with ammo vests or Blackwater T-shirts with the company’s trademark bear claw in the cross hairs, sleeves rolled up.

“Their haircuts were short, and they sported security earpieces and lightweight machine guns. They bossed around journalists and ran Iraqi cars off the roads.’

And, he might have added, hurled mineral water bottles into the windscreens of innocent Iraqi drivers and screamed, ‘F—ING BACK OFF!’

It is this sort of behaviour and character – physically ludicrous, overconfident, culturally insensitive and intellectually challenged – that gives the private security industry such a poor reputation.

Armstrong’s original inspiration for this book came from the disgraceful shooting by a Blackwater team of 16 Iraqi civilians in Baghdad last September.

Blanket immunity, guaranteed by Bremer in one of his last acts in Iraq, is not the best way to deal with this problem of perception.

Armstrong quotes lengthy conversations with Lieutenant Colonel Tim Spicer, founder of the British group Aegis, which at one point had the world’s largest security contract in Iraq.

The story of Aegis, for whom this reviewer established a nationwide civil affairs programme in Iraq, demonstrates how effective a modern private security company can be in a dangerous environment where aid agencies and humanitarian organisations are simply unable to operate.

Whatever one thinks about it, Spicer argues the private security industry is here to stay and there is little reason to doubt it.

Darfur crops up repeatedly here. Frustrated at the unwillingness and inability of sovereign states to supply sufficient troops to the UN/African Union peacekeeping mission, the actress Mia Farrow recently called for a private-sector response, suggesting that Blackwater should intervene.

Spicer envisages a future conflict in a failed state when the UN will debate interminably while the bodies pile up, the international community will wring its hands and eventually a private company will be legally contracted to assist.

As he puts it, ‘Which is worse? Dead babies or a private company?’

Far-fetched? Perhaps not. In 2005, Blackstone launched Greystone, a subsidiary company designed to put a military force into the field – quickly.

In the company’s own words: ‘The Greystone peacekeeping solution provides a flexible force with the ability to provide a properly trained force in a short period of time. The force provides a light infantry solution that is self-contained and self-sufficient. The Greystone peacekeeping programme leverages efficiency of private resources to provide a complete cost-effective security solution.’

Given Khartoum’s hostility to the West, tackling Darfur might be a little optimistic at this stage. Providing a ‘solution’ to lazy corporate jargon would be a good start.

When my wife told me to take a hike, she meant it. To the Lake District. Camping. It was my fault. Had I not rashly cast doubt on her own camping credentials, I would probably not have ended up shivering in a tent just below the top of Scafell Pike, England’s highest mountain, in early February. But when your wife attempts to call your bluff, issuing a challenge and expecting you to duck it, what’s a man to do? It was time to dig out the little-used tent, unpack the down sleeping bag and head north.

Thankfully, I had recruited the best possible travelling companion. Anthony is an old friend who runs his own decorating business in London. He has been visiting the Lake District for 16 years and if he doesn’t quite know it like the back of his hand he’s still the sort of man who gets to the top of a peak and says things like, “That’s Bowfell over there and to the west you’ve got Esk Pike and Great End … ” when all you can see is a series of indiscriminate ridges and hills running into the horizon. Nor, in all those years, has he ever visited in summer, when too many walkers destroy the sense of solitude one comes here for. In short, a winter purist.

Driving up the motorway on a Thursday night we toyed with the idea of Lakeland luxury, amused by the prospect of checking into somewhere unspeakably comfortable and expensive, but this would have been deceitful. Reluctantly we ruled it out. The order of play would be as follows: one night in the Queen’s Head, Troutbeck, as a warm-up; then two chilly nights in a tent, one on a mountain, the other in the National Trust campsite in Langdale. This way honour would be served. The challenge would have been met.

You don’t expect to meet a Frenchman and a pair of Eastern European women working in a traditional 17th-century coaching inn, but these are the cosmopolitan surprises awaiting the visitor to contemporary Lakeland. The cuisine was contemporary, too. I was out of date. For supper I was anticipating a simple pie and chips. Instead, it was a sumptuous dinner of hot smoked salmon, followed by braised belly of pork served with creamed potatoes, caramelised sweet onions, sautéed apples, maple syrup and sage. Good walking food, I told myself, cramming in another pint for good measure. Anthony, somewhat greedily, went for a rich confit of duck leg and then the partridge.

Our guide was the inestimable Alfred Wainwright, a man variously described as gruff, rude, quirky, retiring and generous. Wainwright’s Tour in the Lake District : Whitsuntide 1931 begins with the portentous announcement: “This tour is a most comprehensive one. Limited as we are by time, it is impossible to visit every corner of Lakeland, yet the programme, if followed conscientiously, will lead us everywhere worth mentioning. It will be arduous, but the reward will be well worth the work. It will avoid the tourists, the roads, the picnic spots. It is the claim of this programme that every lake, every valley, every mountain will be seen, if not actually visited.”

Avoiding the tourists is de rigueur for all tourists these days, never mind that the 1m-plus books Wainwright sold on the fabulous fells have caused them to be overrun by tourists for much of the year. This itinerary took him a week. We had a weekend.

Anthony suggested we start with Wainwright’s day three, Keswick to Buttermere. It was 19 miles.

“That sounds like a lot,” I said.

“We could do day five in reverse, Langdale to Wasdale.”

“How far?”

“14½ miles.”

“Hmm. That’s more like it.”

What he didn’t tell me was that it began with a ruinously steep ascent from Langdale and didn’t get much easier after that.

The problem with camping rough – one of its great glories, too – is that you have to carry everything with you. Food, water, tent, sleeping bag, roll mat, cooker, change of clothes. Wainwright we left behind. He was too heavy and his tone irked me.

By the time we had reached Crinkle Crags, which Wainwright judged “Lakeland’s best ridge mile” and Anthony had been burbling away all morning, my back was drenched with sweat, my calves were frozen in shock and my knees shattered. We had surfaced above the clouds for a tantalisingly lovely view, our first, of the mountain wilderness around us, only to be quickly shrouded in cloud once again. Crinkle Crags might have merited Wainwright’s burst of enthusiasm: I barely saw them.

Then, joy of joys, the clouds lifted and suddenly all around us was the essence of Lakeland, rough, still and lonely, a heart-lifting moment for anyone who is moved by mountains. On to Three Tarns, Bowfell and Esk Pike, amid falling temperatures and failing, frozen hands. Water flowed prettily beneath the ice. The wind rising, the hills bare. The emptiness of the scene was the greatest reward for coming here in the heart of winter.

Tempting fate, we pitched the tent in the most exposed spot we could find and one of the most dramatic, a saddle of flat land between Great End and Broad Crag. We had covered 10 or 11 miles. Here I was reduced to a state of collapse for one and a half hours.

I had followed Wainwright’s example by designating myself Leader. Anthony was, as Jim Sharples had been in 1931, Vice-Leader and Consultant. It was important to maintain discipline on an expedition.

“Come and have a look at the sunset.”

“I’m sure it’s lovely.”

“We should go and climb Broad Crag.”

I cursed him. He had younger legs.

The sunset was, of course, wildly beautiful. We were above cloud level and the picture was heavenly, Himalayan, a grey peak or two poking through the clouds in an otherwise clear sky suffused in flames that drifted steadily into lilac. We nibbled on chunks of ice and marvelled at the splendour.

“Time for dinner,” I said.

In addition to his other duties Anthony had been designated Expedition Chef. Hobbling back to the camp, I could think only of food: Cullen Skink soup, beef stew with mashed potato and a pudding of chocolate and biscuits, all washed down with a bottle of claret. Never had a dinner tasted so good. Never was a damp sleeping bag so blissfully restful.

The challenge early on Saturday morning was to reach the summit of Scafell Pike, before returning to Langdale via Langdale Pikes. We had England’s greatest mountain to ourselves: views stretched as far as Snowdonia to the south, Ireland to the west and Scotland to the north.

Much of the route was downhill after that, which was a source of great satisfaction for most of the day until my stupefied knees and thighs were screaming for mercy. At the top of Pike of Stickle a noisy teacher on a mobile phone did much to spoil the serenity of our surroundings. Relief came, after a day of around 11 miles and a boys’ lunch of Scotch egg and pork pie, in the warmth of the Stickle Barn pub.

Anthony started discussing walking options for Sunday. There had been ominous talk of Striding Edge and Helvellyn. Far too vigorous. It was imperative to squash such thoughts immediately.

“You can forget it,” I replied. “I’m not going up another mountain.”

He agreed, with gratifyingly little protest. We settled on a six-mile walk in the Winster Valley – without the slightest hint of a gradient.