The U.K. could be threatened by a large number of "lone wolf" terrorists over the next several years, according to a report released by Michael Clarke, the head of the Royal United Services Institute. Clarke noted that the risk of a lone wolf terrorist attack in the U.K. will increase because about 800 prisoners who have been radicalized in British jails are set to be released over the next five to 10 years. In addition, a large number of convicted terrorists serving sentences are also likely to be released over the next several years.

According to Clarke, these convicted terrorists will likely remain devoted to their radical ideologies and could serve as a source of inspiration for other potential terrorists. Clarke also said that terrorist groups such as al-Qaida in the Arabian Peninsula could use these lone wolf terrorists to launch attacks against high-profile targets in Western nations. Although the chances of these attacks succeeding are low, Clarke said, one will eventually succeed in a major way.