I FOUND myself in the company of some soldiers again last week. It's becoming a regular occurrence. Up until last year I'd had very little contact with the military other than a hazy weekend at Sandhurst in the mid-1980s when I attended the passing-out parade of my best friend from school. At the celebration ball he and his colleagues showed how difficult it was to boogie to the Pasadena Roof Orchestra while wearing full dress uniform and a ceremonial sword.

Then last summer my teenage nephew joined the Black Watch, eager for action and experience, and earlier this year I found myself in Afghanistan writing about Scottish soldiers fighting the Taliban in Helmand province. Last week I was the only civilian in a group of serving officers who were home from the front line and relaxing with a beer, giving vent to their frustrations about their political masters. It was an eye-opening conversation.

Soldiers moaning about politicians is as old as soldiering itself. But these men made a compelling case that British military capability in Afghanistan is being undermined, and lives put at risk, because of a lack of cash and commitment from back home.

The first politician to have their reputation kicked around the room was Alex Salmond. There was contempt for the First Minister's provocative decision to host a dinner in Edinburgh Castle last weekend for Save The Regiments campaigners, who are seen by serving officers as undermining morale within the new Royal Regiment of Scotland. If Salmond does finally get around to paying an official visit to some serving Scottish soldiers instead of pandering to the blazer-and-regimental-tie brigade, he will get a frosty reception.

But Salmond got off lightly compared to Prime Minister Gordon Brown and Defence Secretary Des Browne. Partly it's a question of personal style. When Brown paid a short visit to Afghanistan last year the top brass were struck by the Fifer's lack of warmth and empathy. They were dispirited by his apparent lack of enthusiasm for the difficult task they were engaged in. They contrasted his demeanour with that of Tony Blair. One officer put it this way: "We knew Blair was a bullshitter, but at least he seemed interested."

Another problem for Brown is that the military remembers how, as Chancellor, he saw the armed forces as easy pickings for budget cuts. There's a story about Brown quizzing Royal Navy chiefs about how many personnel it took to man a destroyer. He was told around 400. And how many when in dock, he asked. About 60. Fine, he said, then we'll just pay for 60 full-time sailors and top up from the Naval Reserve when on operations. What he failed to understand was how much the lives of those on a warship depend on them being a highly drilled team. It isn't like bringing in outside catering.

Browne got it in the neck for his stock answer to any problem that can be traced back to decisions taken before he took up his post. Instead of getting his sleeves rolled up and sorting it out, the Defence Secretary's first instinct, according to his critics, is to say: "It wisnae me." But it's more than just a question of personalities. It's also about cash and equipment. Despite the military being stretched to its fullest extent in Iraq, Afghanistan, Kosovo and Sierra Leone, British defence spending as a share of national wealth is the lowest since the 1930s. In 2006, our armed forces accounted for 2.5% of the UK's GDP, compared with 4.4% in 1988.

To be fair, some things have improved in recent years. Medical evacuation and treatment in theatre is now exemplary. Gripes about basics like boots and rifles and body armour are much rarer, and Browne deserves some credit for this. But problems remain. The lack of helicopters in Afghanistan is hampering the British forces' effectiveness. Earlier this year, when the US sent in an additional Marine Expeditionary Unit of 2,400 troops, it came with more air power than Britain's entire 7,500-strong task-force.

Other standard equipment is inadequate. While I was with my new soldier friends last week, word was just coming through of the death of four soldiers in a roadside bomb attack near Lashkar Gah. "They were in a Snatch," said one of the officers, and this news was met with grim nods. The Snatch Land Rovers used to transport personnel are simply not tough enough to deal with the improvised explosive devices that are now the Taliban's weapon of choice. Having spent a tense morning in the back of one of these vehicles in Afghanistan, driving from Musa Qala through hostile territory to a remote army fort, I can vouch for the feeling of vulnerability. But there's a shortage of the more heavily armoured Mastiffs. It's unacceptable that British soldiers are being killed because they are driving in the wrong kind of van.

Money isn't just needed for hardware. The US military has at its disposal something called the Commanders Emergency Response Programme (CERP). Basically it's a slush fund of hundreds of millions of dollars. It's used to build clinics, mosques and schools, construct roads and distribute Korans. It buys goodwill and increased security and ultimately it saves lives. British top brass eye it enviously. Of course, ministers can't just write a blank cheque for the military. But our soldiers are risking their lives for a government policy that has strong public backing. They deserve our respect, and our practical support.

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