THE resignation of a ministerial aide has exposed Gordon Brown’s key justification for the Afghan quagmire – that it is preventing terror attacks on our streets.

As the British death toll has mounted – 213 lost soldiers so far – the Prime Minister has fallen back on arguing that the war is necessary to stamp out terror plots heading to Britain.

On these pages, one defence minister, our very own North Durham MP Kevan Jones, argued the fighting went to “the heart of this country’s national security”.

But this claim has surely been shattered by Eric Joyce, who quit his unpaid defence post, warning that the public no longer believed “the risk of greater terrorism on our streets”

was worth all the pain.

Indeed, I think we owe Mr Joyce a debt of gratitude – because the families of those who have lain down their lives deserve better than the Government’s unconvincing call to arms.

Now, I have the greatest respect for Mr Jones, who has vast experience and knowledge of defence matters after many years on Parliament’s defence select committee.

However, I nearly choked on my coffee when he claimed British troops were in Helmand to prevent a repeat of the July 2005 tube and bus atrocities in London – when those suicide bombers were born and bred in West Yorkshire.

Of course, al Qaida is fighting to return to Afghanistan, but we should recognise that British terror attacks have been homegrown – and motivated by our foreign policy, in particular the bloodsoaked invasion of Iraq.

In fact, Jihadist groups train in Pakistan and Somalia, both of which pose a greater threat than Afghanistan, according to ex- Foreign Office minister and leading diplomat Lord Malloch-Brown.

The return of the Taliban is clearly a frightening prospect for many Afghanis – particularly women – but where is the evidence that the very real terror threat will grow further if they succeed?

Meanwhile, the West risks breeding new terrorists with its mindless “drone” attacks that slaughter hundreds of Afghan civilians from high above, including 70 last Friday.

In any case, waging all-out war until the last possible terrorist has been wiped out is a recipe for many more decades of bodybags coming home. Do we really want that?

I am not suggesting that Britain should withdraw from Afghanistan immediately, because that is politically impossible. But, with the war clearly unwinnable, the day should be nearing quickly.

And there is no doubt that our brave soldiers make a difference. I read this week that six million Afghan children are now in school, including two million girls – up from one million under the Taliban.

But, if the war is worth it, ministers should have the courage to argue for it on the basis that the lives of ordinary Afghanis are getting better, not on the fantasy of protecting the home front.

Could it be that, while the British public cares about ordinary Afghanis, it does not care enough to lose hundreds more soldiers for them – and Mr Brown and Mr Jones know that?

APPARENTLY, a transcript has emerged of the last words of Mary Jo Kopechne, before she plunged to her death on Chappaquiddick Island in 1969.

When the campaign worker told Teddy Kennedy: “I’m pregnant,” he replied: “We’ll cross that bridge when we come to it…”