There is a Wikipedia article for everything: http://en.wikipedia.org/wiki/Opinion_polls_about_9/11_conspi...
And specifically this international WorldPublicOpinion.org poll whose results are compiled there: http://upload.wikimedia.org/wikipedia/commons/2/2b/911worldo...
More or less, the opinion that the US government was behind the attack is clearly in the minority in all polled European countries.
Interesting to see the differences between countries here. That said,one has to be careful with polls in different countries: people's answers are very sensitive to question wording, and I imagine translations can introduce biases easily.
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I'm not challenging your assertion, I'd just like to see it in action and measure it for myself.
Edit: in case you edit or delete your post, this is what I'm asking about: