July 7, 2010, marks the fifth anniversary of the 2005 terrorist attacks on London's Metro system. In 2005, terrorists launched a coordinated attack against London's transportation system, with 3 bombs detonating simultaneously at three different Metro stations and a fourth bomb exploding an hour later on a city bus. In all, there were 52 victims in these bombings with an additional 700 injuries resulting. The four terrorists who executed the attacks were killed in the explosions. On the fifth anniversary of this deadly attack, START provides this background report to examine the degree to which these attacks reflect changing trends in terrorist activity in Great Britain and globally.