Of course it matters. You seem to think that we've arrived at a state of affairs where there are terrorist threats and the issue is whether we can intercept them before they materialise, and that's all we have to think about.
The situation is evolving every day. Things that we do now will contribute either to escalation or reduction of the threats we will face in the future. That's a matter of choice.
We can't just turn off the tap overnight, but we can act now to reduce future threats, in the same way that in Northern Ireland, there are still threats, but recruitment and radicalisation are significantly reduced compared to say 15 years ago.
Yes it is a factor in recruitment of terrorists. I would have thought that's beyond any serious doubt, listening to what the terrorists themselves say, looking at the recruitment material, and considering systematic studies of what leads to radicalisation. Why do you doubt it?
Why do we torture in the first place? Many reasons. Some people just like to impose their will on others, and they tend to gravitate towards situations where they can exercise authoritarian control. In extreme situations, where they think they can get away with it, they will go as far as torture. Others get caught up in a situation, and go along with the prevailing culture - some of the people at Abu Ghraib, or those UK soldiers who may face war crimes prosecutions, may fall into this group.
Maybe some of them actually act with good motives, thinking they might prevent some atrocity, and maybe they are either so caught up in the moment that they don't see the longer term impact, maybe they think it's beyond their pay grade to think strategically, maybe they just have no understanding and awareness of the effect of what they are doing.
Then there is the institutionalised form of humiliation and torture, of which Guantanamo is probably the best example. A propaganda gift for people seeking to recruit terrorists - utterly self-defeating and stupid.
By the way, the people who get tortured may or may not be planning to carry out threats against us. So let's not think "If they weren't guilty, we wouldn't do it to them".
Are we not torturing people now to prevent future attacks? I dont know what some people expect? Maybe Obama should invite Bin Laden to tea so they can agree to disagree, brush it all under the carpet and let it all just blow over? So torturing a couple of 'brothers' gives them the right to murder 3000 innocent human beings?
You walking a very very shakey line of almost saying that it is 'our' fault that 9/11 happened because we started the who affair?
You also talk about maybe they didnt realise the long term effects and act with good motives, i think flying a couple of jets into some skyscrapers is pretty self explanitory.