I don't know if it's that weird - my limited understanding (I know, ignorant American here) of their idealogy is that they think the industrialized West is screwing things up. Isn't one of the justifications for targeting big, symbolic buildings? So "the big, industrialized nations are responsible for screwing up the whole planet" isn't that big of a leap from "the big, industrialized nations are responsible for screwing up our righteous Muslim society".
This is great. Not even The Onion can be funnier than real life all the time. We might not live in the best of all possible worlds, but at least we live in the goofiest.
Build more US-made/operated/maintained wind, solar, geothermal, tidal, hydro, nuclear power supplies.
Every dollar that doesn't go to the terrorist-supporting nation of Saudi Arabia is another dollar fighting them.