It seems that the western world knows why ISIS is fighting, but to be specific, it is not really known. Many groups fight Middle Easterners because of oil, but that is not what ISIS wants. ISIS wants to be the caliphate or leader of the Islamic world. As a matter of fact, they claim to have the caliphate or successor of the Prophet. They want the rest of the world to admit that. The caliphate would be the ultimate leader of all the Muslims in the world. However, not all countries will admit that.
So, ISIS began in 1999 fighting those areas close to them first. These countries were Syria, Iraq and Afghanistan. Then it spread to countries who were supporting the governments of these countries they were fighting against.
