Last Night's TV: Afghanistan: the Battle for Helmand, BBC2Top Gear, BBC3

Today it takes images of smoke pouring from a Kabul hotel popular with Westerners to pull Afghanistan from the inside pages. Almost a decade after British and American troops set about bringing "enduring freedom" to a land to which the origins of 9/11 were apparently traced in a matter of weeks, all that has endured is a sorry stream of news-in-briefs. The names of the dead pool in the back of the mind, along with "explosion" graphics on brown BBC maps, so as to become increasingly meaningless. Do you know how many British pounds or lives have been spent in Afghanistan – or why?

Mark Urban, an army officer-turned-defence correspondent for this newspaper and, lately, diplomatic and defence editor at Newsnight, accepted a mission last night to bring faces and figures to a frustrating and remote war. Afghanistan: the Battle for Helmand filtered more than five years of headlines and bulletins, many of which Urban had delivered from behind his reporter's flak jacket. Oddly, the figures were the most compelling. When, in 2006, breeze blocks were supposed to replace bullets and bombs to lay new foundations for democracy, little more than a thousand British troops arrived to defend an area half the size of England. It's a measure of the challenge they faced that today 30,000 Nato troops do the same job.

The area is Helmand, a region that has become effectively twinned with Wootton Bassett, the RAF market town to which dead soldiers are repatriated. The friends of some of these men supplied many among an impressive platoon of talking heads. Their testimony suggested a huge naivety and lack of preparedness on the part of the battle's architects. The troops arrived as heavily armed interlopers into a maelstrom, rejected as they were by the Taliban and warlords controlling the vast opium trade. Called into the key city of Sangin, by a governor desperate for support, paratroopers with supplies and ammunition to last four days arrived to fortify government buildings. Ninety-five days later they were still fighting as a reconstruction mission became one of death and destruction. Morale ran as low as bullets. Asked what he thought they had achieved, one paratrooper said: "Fucking zero."

It set the tone as Urban charted successive tours that switched tactics every six months, rarely making progress until last year when the Americans kicked out the Brits from the towns they had sacrificed lives to defend. There were signs of hope – an army base that had become a school again, a women's clinic that could have never existed under the Taliban – but, again, the figures spoke volumes. Despite arriving to develop a nation, Britain has spent £12 on war for every £1 given for reconstruction. The total bill: £9bn; more than 350 British lives and unknown thousands of Afghans. Meanwhile, the area half the size of England the British had set out to defend has shrivelled to the size of Kent. One commander called the British mission a "staggering success" while another admitted that "the gap between policy-making and implementation is too wide – we've muddled through." A paratrooper who had lost comrades said: "If anything, stirring up a hornet's nest will bring terrorism to the streets of Britain."

Explosions are never more pointless than when they punctuate an episode of Top Gear, a mission to show off fast cars to an audience that will never be able to afford them that has run for nearly 10 years and, now, 17 series. That its commanders have run out of ideas was evident in last night's repeat of Sunday's opener. It began with a sequence in which the annoying little one drove an oversized military-spec Hummer called the Marauder through the suburbs of Johannesburg, blasting through walls, destroying a McDonald's drive-thru and running over parked cars as he attempted to pitch the £300,000 tank as the perfect city car. Later, he blew a wimpy Hummer into several pieces, before only puncturing the Marauder's tyre with the same amount of plastic explosives.

If I hadn't seen it before, it certainly felt like it. Top Gear must be the BBC's most repeated show (and one of its most lucrative), as any occasional Dave viewer will attest, but it's also surely its most repetitive. Later, the obligatory race took us to Norway where a rally car would do battle with someone hurtling down a bobsleigh track on a tea tray, a stunt that even James May admitted the show had staged before. That the tea tray was occupied not by four men this time but by Amy Williams, an attractive British Olympic champion in Lycra, was perfect for a programme that makes the average sixth-form common room feel like the UN General Assembly. Back at the studio after the race (the car won – whatever), head boy Jeremy Clarkson asked Williams to demonstrate the technique required to steer her skeleton bob (it involves thrusting out ones shoulders to shift left or right). Quickly, the audience, and then the blushing champion, realised it was a playground ploy designed to make her breasts move.

Clarkson was just as car-gasmic in the closing sequence, a celebration of 50 years of the E-Type. It reached its climax on Beachy Head, where dozens of the cars were serenaded by a military brass band on the cliff edge while abseiling marines, perhaps fresh from a tour of Afghanistan, unfurled a giant Union flag over the cliff. Spitfires flew past. All it lacked was a bomb blast – I guess they're saving the explosives for next week.