The debate has largely overlooked a more basic question: How important to terrorist groups is any physical haven? More to the point: How much does a haven affect the danger of terrorist attacks against U.S. interests, especially the U.S. homeland? The answer to the second question is: not nearly as much as unstated assumptions underlying the current debate seem to suppose. When a group has a haven, it will use it for such purposes as basic training of recruits. But the operations most important to future terrorist attacks do not need such a home, and few recruits are required for even very deadly terrorism. Consider: The preparations most important to the Sept. 11, 2001, attacks took place not in training camps in Afghanistan but, rather, in apartments in Germany, hotel rooms in Spain and flight schools in the United States.

In the past couple of decades, international terrorist groups have thrived by exploiting globalization and information technology, which has lessened their dependence on physical havens.

Washington Post: Who’s Afraid of A Terrorist Haven?