“While it would be tempting to posit Paris as another bloody data point explained by our conceptual schema, Paris is in fact cause for broadening and expanding it. Unfortunately, the world faces urban security threats that span a spectrum of organization and lethality. Future threats may look like Mumbai (as has been seen in the Mumbai-like operation against the Westgate shopping mall in Nairobi) or they may resemble Paris. [iii] And there is a large spectrum of threats that occupy the threat envelope in between.”
Source: Urban Siege in Paris: A Spectrum of Armed Assault | Small Wars Journal