I find it confusing to what could happen Afghanistan if the Soviets never had withdrawn.
Well, what kind of hardliner? Gorbachev was generally considered a hardliner when he rose to power.
And the general consensus among those labeled by the CIA as "hardliners" was that some sort of reform was necessary. But obviously a different personality to Gorbachev would have done things differently, and possibly that means the "reforms" are futile deck-chair re-arranging meaning the Soviets are not hurt as they were by Gorbachev's reforms, but nor are their issues addressed, meaning the USSR slowly declines in relative power but remains a military great power well into the 21st Century. Or maybe the reforms actually do some good and after a difficult time in the 1990s, the Soviet Union manages to tread water in terms of relative economic performance or starts to slowly close the gap, though not fast enough to avoid being overtaken by China as the largest economy in the Second World.
(As you might be able to tell, I don't find the habit of Western Sovietology to talk about hardliners vs moderates vs liberals as terribly useful when discussing Soviet politics as the underlying political dynamics of the USSR depended on personal relationships, favor trading and personal views that could lead to surprising alignments between Soviet politicians - a fellow like Suslov could be a "hardliner" on the subject of western relations, while at the same time being a "liberal" on the subject of relations between the Soviets and their allies/clients and so on.)
Assuming that "hardliner" in this context is someone who doesn't trust Thatcher and Reagan and who believes that the Soviet military must stay in Afghanistan indefinitely or else the country will become a CIA puppet, while also reforming the USSR enough to remain the main obstacle to US domination of the world, but not enough to avoid noticeable weakness in the 90s, well... Eventually the Soviets are going to have to settle things in Afghanistan by sitting down the tribal coalition fighting them with government of the Afghan cities and come to some sort of compromise. I can see a situation where all the sides eventually get tired of fighting and the compromise looks like "Soviet base is kept in Kabul, the city people keep their noses out of the countryside and Soviet "development aid" to both the tribes and the Kabul regime bribes both into keeping a reasonable common front against other foreigners. So the Soviets haven't totally withdrawn, and the civil war basically ends. It would take a few more years busting heads and getting shot at in Afghanistan to do, but it is possible. I think for the Kabul regime to be given absolute control over the whole country would take more time than GenSec "hardliner" will have in office, and in any case, the Soviets aren't really interested in crushing rural Afghanistan (indeed part of why they intervened was because they opposed the Kabul regime trying to go all Stalin-mode on their rural countrymen - they wanted a stable and boring Afghanistan, not a textbook Marxist-Leninist Afghanistan). So long as Afghanistan isn't leaning pro-west or trying to invade Pakistan, the Soviets will be happy. Indeed, one of the challenges in making your scenario happen is making it so the Soviets don't add complete withdrawal to the bargain, and instead bleed more for the sake of keeping some bases in the country, which isn't super likely.
So what does Bin Laden do in this scenario? Well, it's quite possible Bin Laden bravely dies acting as a meat-shield, protecting some far more worthy Afghan freedom fighter. But let's assume "no".
Even if the Soviets are able to secure an uneasy peace in Afghanistan itself by say the mid-90s, I'll bet that there will be plenty of anti-Soviet fighters in the Pashtun borderlands of Afghanistan getting some level of support from Pakistan and the US. So potentially Bin Laden keeps on with that project. But on the other hand, Soviet power in the middle east as a whole is likely to decline in the wake of the shattering American success in the Gulf War (I'm assuming that Saddam isn't butterflied into not seeking war somehow and that Bush sr. is still the President and makes similar calls in TTL to OTL) and the presence of US troops in Saudi Arabia itself would still be deeply upsetting to Bin Laden. He may also have some resentment about the US not supporting the Mujaheddin in Afghanistan ENOUGH, so while it is possible that Bin Laden remains fixated on the Atheist Soviets, I see a good chance that he would decide that opposing the US was more necessary in any case.
That said, he may try recruiting Soviet Muslims instead of Saudis for his main attack on the US in TTL, in the hopes that he can strike at the US AND encourage the US to strike back against the USSR.
9/11 leading to a US-Soviet nuclear war is not entirely out of the question.
But that's assuming a successful 9/11. The operation needed a goodly measure of luck to come off in OTL, and that's not guaranteed in TTL, especially as a weak, but still dangerous Soviet Union being around would mean more spending on national security. But of course, that spending would largely be busy with watching for Soviet threats. So Bin Laden could still find a gap and get a blow in.
Regards,
fasquardon
