George W. Bush hardly finished his declaration of war on terror when the U.S. government turned its attention toward a trinational region where Argentina, Brazil, and Paraguay meet, called the triple frontera (Triple Border, in Spanish) and the tríplice fronteira (in Portuguese). My article traces how border residents of Muslim Lebanese origins responded to this post-9/11 U.S. counterterrorist encompassment. I suggest that Arabs publicly mobilized through three media- and state-sponsored initiatives that sought to combat U.S.-derived suspicions. Beginning in September 2001, they led the Peace without Frontiers movement, bringing together some forty-five thousand Triple Border residents; in late 2002, they participated in a border city government’s lawsuit against the Cable News Network (CNN) for defamation; and in mid-2003, they supported the publicity campaign that satirized the alleged visit of Osama bin Laden. Arabs crossed ethnic and national boundaries in order to collaborate with South American media and state powers against the U.S. war on terror. At the same time U.S. counterterrorism traversed the continent, Brazilians and Paraguayans of Arab origins mobilized across the post-9/11 Americas as well.