Grievance Explanations and the Politics of Fantasy
If you think that the London attacks were caused by the US/UK invasion of Iraq, and regard this as evidence why we shouldn't be in Iraq, you're saying that had we not gone to Iraq attacks like London would not have happened.
Sort of. When we weren't in Iraq, we had a sanctions/inspections/no-fly policy that killed tens of thousands if not hundreds of thousands of Iraqis. That policy didn't lead to a bombing in London; it merely led to two bombings of US installations in Saudi Arabia, two embassies destroyed in East Africa, one bombing of a US naval vessel, the attempted destruction of the river crossings into NYC, the attempted destruction of LAX--and 9/11. So if you don't think we should have invaded Iraq, and think we should have stuck to our old policy, you have to face the fact that the old policy "caused" 9/11 etc as surely as the occupation "caused" London.
If you don't think we should have had sanctions/inspections or a no-fly policy, you must have no objection to full-scale Iraqi development of WMD. So if those WMD had been developed, you either need to say "Iraqi WMD development--no problem!" and show why it wasn't, or explain how Iraqi WMD development would have been precluded without sanctions, inspections or war.
If you think we shouldn't have liberated Kuwait at all, and shouldn't have gotten involved with Iraq at all, you should explain what policy options there were had Iraq threatened the Saudi (or other Gulf) oil fields.
So which policy do you want? The one that led to London, the one that led to 9/11, the one that would have led to a nuclearized Iraq, or the one that might well have led to the Iraqi hijacking of the Saudi oil fields?
Or is it that you want the policy option that consists in the fantasy that you don't have to think about stuff like this?