The videotape of the suicide bomber Mohammad Sidique Khan has switched the focus of the London bombings away from the establishment view of brainwashed, murderous individuals and highlighted a starker political reality. While there can be no justification for horrific killings of this kind, they need to be understood against the ferment of the last decade radicalising Muslim youth of Pakistani origin living in Europe.

During the Soviet occupation of Afghanistan in the 1980s, the US funded large numbers of jihadists through Pakistan's secret intelligence service, the ISI. Later the US wanted to raise another jihadi corps, again using proxies, to help Bosnian Muslims fight to weaken the Serb government's hold on Yugoslavia. Those they turned to included Pakistanis in Britain.

According to a recent report by the Delhi-based Observer Research Foundation, a contingent was also sent by the Pakistani government, then led by Benazir Bhutto, at the request of the Clinton administration. This contingent was formed from the Harkat-ul- Ansar (HUA) terrorist group and trained by the ISI. The report estimates that about 200 Pakistani Muslims living in the UK went to Pakistan, trained in HUA camps and joined the HUA's contingent in Bosnia. Most significantly, this was "with the full knowledge and complicity of the British and American intelligence agencies".

As the 2002 Dutch government report on Bosnia makes clear, the US provided a green light to groups on the state department list of terrorist organisations, including the Lebanese-based Hizbullah, to operate in Bosnia - an episode that calls into question the credibility of the subsequent "war on terror".

For nearly a decade the US helped Islamist insurgents linked to Chechnya, Iran and Saudi Arabia destabilise the former Yugoslavia. The insurgents were also allowed to move further east to Kosovo. By the end of the fighting in Bosnia there were tens of thousands of Islamist insurgents in Bosnia, Croatia and Kosovo; many then moved west to Austria, Germany and Switzerland.

Less well known is evidence of the British government's relationship with a wider Islamist terrorist network. During an interview on Fox TV this summer, the former US federal prosecutor John Loftus reported that British intelligence had used the al-Muhajiroun group in London to recruit Islamist militants with British passports for the war against the Serbs in Kosovo. Since July Scotland Yard has been interested in an alleged member of al-Muhajiroun, Haroon Rashid Aswat, who some sources have suggested could have been behind the London bombings.

According to Loftus, Aswat was detained in Pakistan after leaving Britain, but was released after 24 hours. He was subsequently returned to Britain from Zambia, but has been detained solely for extradition to the US, not for questioning about the London bombings. Loftus claimed that Aswat is a British-backed double agent, pursued by the police but protected by MI6.

One British Muslim of Pakistani origin radicalised by the civil war in Yugoslavia was LSE-educated Omar Saeed Sheikh. He is now in jail in Pakistan under sentence of death for the killing of the US journalist Daniel Pearl in 2002 - although many (including Pearl's widow and the US authorities) doubt that he committed the murder. However, reports from Pakistan suggest that Sheikh continues to be active from jail, keeping in touch with friends and followers in Britain.

Sheikh was recruited as a student by Jaish-e-Muhammad (Army of Muhammad), which operates a network in Britain. It has actively recruited Britons from universities and colleges since the early 1990s, and has boasted of its numerous British Muslim volunteers. Investigations in Pakistan have suggested that on his visits there Shehzad Tanweer, one of the London suicide bombers, contacted members of two outlawed local groups and trained at two camps in Karachi and near Lahore. Indeed the network of groups now being uncovered in Pakistan may point to senior al-Qaida operatives having played a part in selecting members of the bombers' cell. The Observer Research Foundation has argued that there are even "grounds to suspect that the [London] blasts were orchestrated by Omar Sheikh from his jail in Pakistan".

Why then is Omar Sheikh not being dealt with when he is already under sentence of death? Astonishingly his appeal to a higher court against the sentence was adjourned in July for the 32nd time and has since been adjourned indefinitely. This is all the more remarkable when this is the same Omar Sheikh who, at the behest of General Mahmood Ahmed, head of the ISI, wired $100,000 to Mohammed Atta, the leading 9/11 hijacker, before the New York attacks, as confirmed by Dennis Lormel, director of FBI's financial crimes unit.

Yet neither Ahmed nor Omar appears to have been sought for questioning by the US about 9/11. Indeed, the official 9/11 Commission Report of July 2004 sought to downplay the role of Pakistan with the comment: "To date, the US government has not been able to determine the origin of the money used for the 9/11 attacks. Ultimately the question is of little practical significance" - a statement of breathtaking disingenuousness.

All this highlights the resistance to getting at the truth about the 9/11 attacks and to an effective crackdown on the forces fomenting terrorist bombings in the west, including Britain. The extraordinary US forbearance towards Omar Sheikh, its restraint towards the father of Pakistan's atomic bomb, Dr AQ Khan, selling nuclear secrets to Iran, Libya and North Korea, the huge US military assistance to Pakistan and the US decision last year to designate Pakistan as a major non-Nato ally in south Asia all betoken a deeper strategic set of goals as the real priority in its relationship with Pakistan. These might be surmised as Pakistan providing sizeable military contingents for Iraq to replace US troops, or Pakistani troops replacing Nato forces in Afghanistan. Or it could involve the use of Pakistani military bases for US intervention in Iran, or strengthening Pakistan as a base in relation to India and China.

Whether the hunt for those behind the London bombers can prevail against these powerful political forces remains to be seen. Indeed it may depend on whether Scotland Yard, in its attempts to uncover the truth, can prevail over MI6, which is trying to cover its tracks and in practice has every opportunity to operate beyond the law under the cover of national security.

· Michael Meacher is the Labour MP for Oldham West and Royton; he was environment minister from 1997 to 2003.

massonm@parliament.uk

Significantly, Sheikh is also the man who, on the instructions of General Mahmoud Ahmed, the then head of Pakistan's Inter-Services Intelligence (ISI), wired $100,000 before the 9/11 attacks to Mohammed Atta, the lead hijacker. It is extraordinary that neither Ahmed nor Sheikh have been charged and brought to trial on this count. Why not?

Ahmed, the paymaster for the hijackers, was actually in Washington on 9/11, and had a series of pre-9/11 top-level meetings in the White House, the Pentagon, the national security council, and with George Tenet, then head of the CIA, and Marc Grossman, the under-secretary of state for political affairs. When Ahmed was exposed by the Wall Street Journal as having sent the money to the hijackers, he was forced to "retire" by President Pervez Musharraf. Why hasn't the US demanded that he be questioned and tried in court?

Another person who must know a great deal about what led up to 9/11 is Khalid Sheikh Mohammed, allegedly arrested in Rawalpindi on March 1 2003. A joint Senate-House intelligence select committee inquiry in July 2003 stated: "KSM appears to be one of Bin Laden's most trusted lieutenants and was active in recruiting people to travel outside Afghanistan, including to the US, on behalf of Bin Laden." According to the report, the clear implication was that they would be engaged in planning terrorist-related activities.

The report was sent from the CIA to the FBI, but neither agency apparently recognised the significance of a Bin Laden lieutenant sending terrorists to the US and asking them to establish contacts with colleagues already there. Yet the New York Times has since noted that "American officials said that KSM, once al-Qaida's top operational commander, personally executed Daniel Pearl ... but he was unlikely to be accused of the crime in an American criminal court because of the risk of divulging classified information". Indeed, he may never be brought to trial.

A fourth witness is Sibel Edmonds. She is a 33-year-old Turkish-American former FBI translator of intelligence, fluent in Farsi, the language spoken mainly in Iran and Afghanistan, who had top-secret security clearance. She tried to blow the whistle on the cover-up of intelligence that names some of the culprits who orchestrated the 9/11 attacks, but is now under two gagging orders that forbid her from testifying in court or mentioning the names of the people or the countries involved. She has been quoted as saying: "My translations of the 9/11 intercepts included [terrorist] money laundering, detailed and date-specific information ... if they were to do real investigations, we would see several significant high-level criminal prosecutions in this country [the US] ... and believe me, they will do everything to cover this up".

Furthermore, the trial in the US of Zacharias Moussaoui (allegedly the 20th hijacker) is in danger of collapse apparently because of "the CIA's reluctance to allow key lieutenants of Osama bin Laden to testify at the trial". Two of the alleged conspirators have already been set free in Germany for the same reason.

The FBI, illegally, continues to refuse the to release of their agent Robert Wright's 500-page manuscript Fatal Betrayals of the Intelligence Mission, and has even refused to turn the manuscript over to Senator Shelby, vice-chairman of the joint intelligence committee charged with investigating America's 9/11 intelligence failures. And the US government still refuses to declassify 28 secret pages of a recent report on 9/11.

It has been rumoured that Pearl was especially interested in any role played by the US in training or backing the ISI. Daniel Ellsberg, the former US defence department whistleblower who has accompanied Edmonds in court, has stated: "It seems to me quite plausible that Pakistan was quite involved in this ... To say Pakistan is, to me, to say CIA because ... it's hard to say that the ISI knew something that the CIA had no knowledge of." Ahmed's close relations with the CIA would seem to confirm this. For years the CIA used the ISI as a conduit to pump billions of dollars into militant Islamist groups in Afghanistan, both before and after the Soviet invasion of 1979.

W ith CIA backing, the ISI has developed, since the early 1980s, into a parallel structure, a state within a state, with staff and informers estimated by some at 150,000. It wields enormous power over all aspects of government. The case of Ahmed confirms that parts of the ISI directly supported and financed al-Qaida, and it has long been established that the ISI has acted as go-between in intelligence operations on behalf of the CIA.

Senator Bob Graham, chairman of the Senate select committee on intelligence, has said: "I think there is very compelling evidence that at least some of the terrorists were assisted, not just in financing ... by a sovereign foreign government." In that context, Horst Ehmke, former coordinator of the West German secret services, observed: "Terrorists could not have carried out such an operation with four hijacked planes without the support of a secret service."

That might give meaning to the reaction on 9/11 of Richard Clarke, the White House counter-terrorism chief, when he saw the passenger lists later on the day itself: "I was stunned ... that there were al-Qaida operatives on board using names that the FBI knew were al-Qaida." It was just that, as Dale Watson, head of counter-terrorism at the FBI told him, the "CIA forgot to tell us about them".

· Michael Meacher is Labour MP for Oldham West and Royton. He was environment minister 1997-2003

massonm@parliament.uk

So "brave" Muammar Gadafy has agreed on the importance of combating terrorism. A handshake with Tony Blair has sealed his re-entry into the international community, with contracts worth several hundred million pounds for Shell and BAE to follow. His compliance in opening up Libya to nuclear weapons inspectors has been spun as a major triumph in the "war on terror". The motives, however, are rather more cynical.

Negotiations for a rehabilitated public image for Colonel Gadafy, linked to improved western access to Libyan oil, began to surface in August 2002 with the visit by the Foreign Office minister, Mike O'Brien, to Sirte, near Tripoli. As the BBC said at the time, Libya was keen to re-enter the world economy, and the UK did not want to lose out on potentially lucrative oil contracts.

For both the UK and US, an energy crisis is looming. The latest BP statistical review of world energy predicted that UK proven oil and gas reserves will last, respectively, only 5.4 and 6.8 years at present rates of use. It has been estimated that by 2020 the UK could be dependent on imported energy for 80% of its needs. The US energy department has calculated that net imports of oil, already at 54%, will rise to 70% by 2025 because of growing demand and declining domestic supply.

Libya produces high-quality, low-sulphur crude oil at very low cost (as low as $1 per barrel in some fields), and holds 3% of world oil reserves. It also has vast proven natural gas reserves of 46 trillion cubic feet, but actual gas reserves are largely unexplored and estimated to total up to 70 trillion cubic feet.

The problem of access to Libyan hydrocarbons was Gadafy's record of running a state terrorist machine - responsible for arming the IRA, the shooting of PC Yvonne Fletcher and the bombing of Pan Am flight 103 over Lockerbie in 1988. Britain had even, according to the former MI5 agent David Shayler, paid £100,000 to an al-Qaida cell in Libya to assassinate Gadafy in 1996, and then granted asylum to a member of the cell named Anas al-Liby, who lived in Manchester until 2000.

Moreover, just two months before Gadafy's pact with the west was announced on December 19 last year, Libya was caught trying to import nuclear technology from Malaysia. If it had been Saddam Hussein, no doubt the deal would have been scotchedon the grounds of his unreliability and bad faith. But it is remarkable how sometimes terrorists suddenly turn into "statesmanlike and courageous" friends (to use Jack Straw's phrase).

None of the history of mutual hostility over the past two decades prevented a deal along these simple lines: we accept your acknowledgement of guilt over flight 103, you open up your WMD programmes to inspection, and then both of us can start benefiting from trading your oil again. The weakness of this deal as presented, however, is that it appears that Libya didn't have any WMD, other than chemical weapons no longer likely to be useable. The International Atomic Energy Agency stated last December that "Libya was not close to building a nuclear weapon". Indeed, Libya had itself nine months earlier proposed inspections, so the west's triumphalism says more about the US-UK desire to placate domestic critics than about forcing any fundamental policy change on a recalcitrant Gadafy.

Nor is this rapid shift from terrorist to statesman confined to Libya. The US backing of Islamic terrorism in the Balkans provides another example. As the official Dutch inquiry into the 1995 Srebrenica massacre has now revealed, a secret alliance was formed between the Pentagon and radical Islamist groups to assist the Bosnian Muslims in violation of the UN arms embargo. A vast secret conduit of weapons smuggling through Croatia was organised by US, Turkish and Iranian clandestine agencies, together with Afghan mojahedin and pro-Iranian Hizbullah. Aircraft from Iran Air were used, joined by a US-sponsored fleet of C-130 Hercules.

The 78-day bombing of Yugoslavia in the spring of 1999, directed by the US general Wesley Clark, was said to be stopping an alleged "genocide" by the Serbs in Kosovo (some 2,000 bodies were later exhumed, a horrifying number but far short of the 100,000 the US predicted). The US goal was to assist the Kosovo Liberation Army (KLA). Yet the year before, the US state department had branded the KLA a terrorist organisation, financing its operations from the heroin trade and funds from Islamic countries and individuals, including Osama bin Laden.

As James Bissett, the former Canadian ambassador to Yugoslavia, has subsequently reported: "This did not stop the US from arming and training KLA members in Albania and sending them back into Kosovo to assassinate Serbian mayors, ambush Serbian policemen and intimidate hesitant Kosovo Albanians ... Despite a UN arms embargo, and with the support of the US, arms, ammunition and thousands of fighters were smuggled into Bosnia to help the Muslims ... Bin Laden and his network were also active in Kosovo, and KLA members trained in his camps in Afghanistan and Albania." According to reports in April 1999, assistance was also provided by Britain's SAS.

Through much of the 1990s, US support for Islamic militants in former Yugoslavia was backed up by covert US airdrops of arms, especially at Tuzla in northern Bosnia. These took place in the face of Operation Deny Flight, the UN-imposed and Nato-policed no-fly zone over Bosnia. The US House of Representatives also failed to authorise the war under the War Powers Act, making it illegal (shades of Iraq). But the airdrops were only the tip of the iceberg. Retired US officers heading Military Professional Resources Inc, a private paramilitary firm based in Virginia, planned the bloody Croatian "liberation" of the Serb-held Krajina enclave, which resulted in the ethnic cleansing of 200,000 Serbs.

US goals in the use of the KLA as a proxy force, similar to the funding of the Contras against the leftwing Sandinista government in Nicaragua in the 1980s, were partly to remove Milosevic and break up Yugoslavia as one of the remaining Communist regimes. But related motives were to break Russia's monopoly over oil and gas transport routes and secure pro-western governments in the strategic Black Sea-Caspian Sea oil-rich basin. A crucial oil corridor, called the Trans-Balkan pipeline, designed to become the main route to the west for oil and gas extracted in central Asia, was to run from the Black Sea to the Adriatic via Bulgaria, Macedonia near the border with Kosovo, and Albania. Another was to run across Serbia to Adriatic ports in Croatia and Italy, fed by a pipeline running from a Black Sea port in Romania.

The implications of this are stark. The US played a major role in creating and sustaining the mojahedin to fight the invading Soviet army in the Afghan war of 1979-92. Then from 1992-95 the Pentagon assisted the movement of thousands of Islamic fighters from central Asia to fight alongside Bosnian Muslims and remove the Milosevic barrier, and so extend US influence in a key area of oil geopolitics - a "pact with the devil", as Richard Holbrooke, America's former chief Balkans peace negotiator put it. It has proved quite another thing to rein them back in again. Before President Bush trumpets his dedication to his war on terror, he should reflect on his country's links with terrorism over the past decade where it has suited US interests.

· Michael Meacher was environment minister, 1997-2003.