What was Al Queda doing blowing a hole in the USS Cole and bombing our embassies in Dar es Salaam and Nairobi and attacking Khobar Towers in Saudi Arabia? Damn idiots, didn't they know that Bush wasn't yet President so they should wait to attack until he was.
What was it doing? It was trying to damage the US, USS Cole happened in Yemen, others happened anywhere but Iraq too.
Was it Clinton's fault that these happened? In part, again, as US President he gets some blame, I would not put much.
US foreign policy with Islamic countries over a long period of time helped, especially the situation with Israel has made the US a target of extremist Islamists. Kuwait played a small part, I wouldn't put much blame on Bush himself, US policy was moving towards oil at the time anyway, and US interests. But it can play a part in explaining how things happened.
Even 9/11 happened. It wasn't Bush W.'s fault as far as I know. (Depending on conspiracy theories and unknown things etc). It happened as a result of US foreign policy since the beginning of Israel as a nation, and even British foreign policy beforehand.
But you're missing the point. The point isn't just black and white, simple enough for a primary school kid to understand. It's complex.
In 2001 9/11 happened. There were plenty of choices out there, one of which was not to invade Iraq, but Bush did it anyway. Afghanistan was a choice, he took it too. It also helped. There were other choices concerning Afghanistan that was not troops on the ground.
But not only what Bush did with military action, it was also what he did with his speech. He made al-Qaeda the coolest kids in the anti-American terrorist movement. If you were anti-American and wanted to fight the US, then become al-Qaeda.
Also, Obama does not want troops on the ground in Syria and Iraq. Why not? You'd be giving extremists a target. Bush not only gave them a target (many moved from Afghanistan to fight in Iraq) but he also set up the perfect situation for them. He got rid of the Iraqi police and army and therefore a power vacuum the US armed forces (with British) could not hope to fill.
So terrorist groups could grow, they could use this to recruit more easily, they were helped massively by Bush's incompetent policies with complete lack of foresight, with complete lack of learning from history. The US believed it could take out a country, rebuild it in a mould it liked and all would be well. It's called arrogance, it happened in Vietnam, it happened in Iraq.
The point isn't al-Qaeda. The point is the development of al-Qaeda to a pain in the ass group run by a few loonies, to a major international organization that has changed the face of international foreign affairs for a lot of countries.