The files reveal while the US provided far more in financial and material terms to the Afghan jihad, the UK played a direct combat role, with covert British forces – in particular the SAS – practically supporting resistance groups.
Current and former SAS officers trained numerous jihadi forces at MI6 and CIA bases in Saudi Arabia and Oman, teaching them sabotage, reconnaissance, attack planning, arson, and how to use explosive devices, heavy artillery such as mortars, and attack aircraft, among other things.
The SAS also, in conjunction with US special forces, training Pakistan's Special Services Group (SSG), which led insurrectionary operations in Afghanistan, in the hope officers could impart their learned expertise directly to jihadists in Afghanistan.
Mujahideen were also trained
in the UK – snuck into the country as tourists, they spent three-weeks at a time in camps situated in Scotland and the North of England. A key trainer was Brigadier General Rahmatullah Safi, former senior officer in the royal Afghan army who, who'd lived in the UK since the 1970s.
He trained as many as 8,000, continuing to live in the UK well into the 1990s, when he was regarded
by the United Nations as the Taliban's key representative in Europe, by then the undisputed rulers of Afghanistan.
Another key individual supported by the UK was Hadji Abdul Haq, of the Hizb-i-Islami group. He was provided 600 'Blowpipe' anti-aircraft missiles missiles and maps of Soviet military positions by MI6, and introduced to the CIA.
Unlike many other jihadist groups, Haq had no qualms about targeting innocent civilians, arranging the infamous September 1984 bombing
at Kabul airport, which killed 28, and attacks on hotels.
Despite this, in March 1986 he was welcomed to the UK as a guest of Thatcher. An official spokesperson explained at the time the Prime Minister had "a degree of sympathy with the Afghan cause" as they were "trying to rid their country of invaders, which you cannot say of the ANC or PLO."
In reality, far in excess of a "degree of sympathy" with Afghan fighters, by that point the UK's role in the conflict entailed directly military involvement not only in Afghanistan, but the Central Asian republics of the Soviet Union.
MI6 organized and executed "scores" of terror strikes in Tajikistan and Uzbekistan, on the basis Soviet Army troop supplies flowed from these areas – the first direct Western attacks on the Soviet Union since the 1950s. MI6 also funded the spread of extremist Islamic literature in the Soviet republics.
Soviet forces would eventually leave Afghanistan February 15 1989, leaving the government of Mohammed Najibullah to be overthrown in 1992. By 1996, the Taliban had taken control of the country, during which time strong restrictions were imposed on women, public executions were reinstituted, and international aid was prevented from entering Afghanistan, leading to thousands of deaths through starvation.