According to the Washington Post, the situation in Mumbai is finally under control. Once again, this attack demonstrated how much damage a small, motivated group of terrorists can inflict. Could this type of attack happen in the U.S.? Unfortunately, yes. A large country with an open society such as the U.S. is particularly vulnerable. We'd like to think that our police & counterterrorism forces would be more effective in a similar situation, but that's doubtful. An attack inside luxury hotels gives terrorists a large number of potential victims, and numerous opportunities to take hostages. In addition, travelers and workers in those type of hotels are unlikely to be armed, and have little means of resistance. The presence of so many innocent civilians in the buildings greatly impedes the counterterror response -- as seen in Mumbai. The Indian forces couldn't just blast their way into the hotels, so instead you had a siege situation that lasted three days -- all caused by only 15 terrorists, according to latest reports.
It's fashionable in some circles to downplay the threat of terrorism, particularly of the radical Islamic variety. Mumbai is yet another reminder that the threat is real. People who recognize it and want to take action against it aren't "fearmongering," engaging in the "politics of fear," or whatever other ridiculous jargon is often used to dismiss them.