Yes - and a terrorist recruitment center. And a transfer station for espionage. And, perhaps worst of all: a symbol of victory for the savages who destroyed the World Trade Center.
The proposed mosque is intended not as a symbol of peaceful coexistence, but rather as a taunt.
We as Americans need not tolerate such a purposeful insult. We would be foolish to countenance the erection on sacred ground of a structure whose walls will echo with calls for further acts of violence against us. If it is built - it will not stand.