The above graph shows the top 40 worst terrorist attack that have been executed in the history between year 1982 to 2016. The graph shows us that the worst terrorist attack has happened in The United States of America. One of the reason we can think of USA being the target to terrorist is it being the world power and it having the highest global economy and hub for major firms. So, it becomes a go to target for terrorist as the attack becomes a world news.