Although it didn't happen in modern times the Crusades still effect tensions between the western world and the middle east, as well as how both worlds view each other. Another topics could be ISIS. For the first one its the mater of changing almost a thousand years of feud between the two worlds, ISIS is most likely because of that feud. The problem with ISIS though is we don't know how many there are or where they all are. We need to consider the facts and history behind both issues when seeking a solution.
