You assume that the mosque will be built for the purpose of provocation; but is that assumption correct?

Who says the muslims who'll be praying there agree with the viewpoints of the nutcases who flew planes into buildings?

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How about looking at it from another angle?

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The nutjobs flew planes in buildings to provoke your country. They wanted you to start hating all Muslims, because they want eternal war and conflict (or at least until all infidels are exterminated).

Instead of letting yourself be provoked to that, you ruin their plans by allowing Muslims to build a house of prayer only two blocks away from Ground Zero. America will always be a free country, no matter how many planes those nutjobs fly into your buildings. Take that, extremists.