Improvised explosive devices in Urban Warfare in the West
The development of the concept of asymmetric warfare is one of the worst aspects of this century, There are no rules and no limits, therefore, anything goes anywhere yet. In the common concept of total war, terrorism escapes by traditional battlefield to creep up gradually in cities. We saw it in 2001 in New York, and we have seen this happening in London in 2005 and in Madrid in 2004.
Source: Defense Online