Britain's Terror Heartland

Seven years after 9/11, the US-led war on terror rumbles on. The new frontline is Pakistan's remote tribal area near its border with Afghanistan, where soldiers from the Pakistan army are fighting diehard al-Qaeda and Taleban-linked militants who have made the region their home.

It is in this restive area that Osama bin Laden is believed to be hiding and there where many terror attacks - inside Pakistan itself, over the border in Afghanistan, and further afield - are planned, prepared and launched.

The militants in Bajaur use a network of tunnels to launch their attacks

It is a wild place normally off limits to foreigners, but in Panorama: Britain's Terror Heartland, distinguished reporter and al-Qaeda expert Jane Corbin travels to the hazardous and forbidding region.

She meets those fighting on all sides, from US and Pakistani soldiers to would-be suicide bombers, as she investigates how what happens there has become key to the security of all of us.

Jane visits Bajaur the epicentre of the fighting between the militants and Pakistan's forces.

The Pakistan army says it has lost nearly 100 men since the fighting began in August and it is not hard to see why, as Jane is shown some of the extensive network of underground tunnels which the militants use to both attack and escape.

Bajaur is being won back but inch by inch, but it has taken three months to secure 13 kilometres of road.

Forced to flee

And as Jane reports, there is a heavy toll being exerted on the local people. She visits Loesam, a town home which was razed to the ground after a group of Pakistani troops were ambushed by Taleban militants there in August.

Loesam was razed to the ground after a Taleban ambush in August

The hundreds of thousands of residents who have fled the fight in Bajaur now live in squalid refugee camps further south. Already poor, they now have nothing.

On the border, the mountains of Bajaur become the mountains of Kunar in Afghanistan.

Four years ago suicide bombings were almost unknown in Afghanistan, but this is no longer the case as militants flow across the border from Pakistan and launch attacks, killing hundreds of Afghans and Westerners in the process.

In Kunar Jane meets US commander Mark Milley, who is leading US troops in the effort to trap the militants between the hammer of the Pakistan army's offensive in Bajaur and the anvil of US forces on the Afghan side.

Fortified buildings

But as she reports, the prospect of a stable Afghanistan is a long way off.

Even the streets of the capital, Kabul, are no longer safe, with terror attacks almost every day.

In a stark contrast to earlier visits where Jane says she could wander the bazaars and markets at will, it is now a matter of scurrying between a heavily curtained minibus and fortified buildings much of the time.

But it is not just Afghanistan's security which is threatened by what goes on in the tribal areas of Pakistan - insurgents fighting British troops in Afghanistan's Helmand province are supplied and reinforced from over the border and many of those behind terror plots here in the UK were either trained or radicalised there.

Pakistan itself is seeing its security threatened, most notably with the September bombing of the Marriott hotel in Islamabad which killed at least 53 people.

And the recent terror attacks India, in which 188 people died, have upped the pressure on Pakistan's government to prove it can regain the upper hand in the restive north.

One militant was captured alive from the Mumbai attacks. Azam Amir Qasab is in police custody and Indian police have said he is "certainly" from Pakistan, though Islamabad denies that Pakistan is involved.

Panorama: Britain's Terror Heartland - BBC One 8.30pm on Monday 15 December