Well, I suppse you could talk about British terrorists, but that has more to do with the fact Islam is a trans national religion, and so things that effect one Muslim nation, tend to have an effect on Muslims in other places.
As for why Pakistanis have been involved in Kashmir or India… Simply because Pakistanis have an emotional connection to the Kashmir, where India has commited human rights violations and continues to occupy ilegally.
Why is that so hard to comprehend? You occupy an entire region with Millions of people, and then you wonder when your attacked. Wake up, your as oblivious as your govt.