On Jan. 8, the U.S. Senate Committee on Homeland Security and Governmental Affairs heard testimony from a number of experts about the lessons learned from the Nov. 26 Mumbai attack . According to Sen. Susan Collins (R-Maine), the Mumbai attack deserves attention because it raises important questions about the plans of U.S. authorities to prevent, prepare for and respond to similar attacks directed against targets in the United States. As we've previously pointed out, the tactics employed in the Mumbai attack were not new or remarkable , although the attackers did incorporate some tactical innovations due to their use of modern technology. As shown by a long string of historic terror attacks, armed assaults can be quite effective. There are a number of factors, however, that would reduce the effectiveness of a similar attack inside the United States or many Western European countries.