The Guggenheim’s alarming action continues a growing worldwide trend in which threats of violent protest are silencing artistic expression and posing a danger to free speech in general. Whether or not the provocations of artists are defensible or morally unacceptable, we need to take an uncompromising position against threats of violence. When cultural institutions cave in to such threats, others who are convinced of the moral rectitude of their cause are encouraged to embrace similar tactics. This time it is animal rights activists. Next time it could be religious or political extremists.