There are two types of Muslims. The violent jihadists converting to Islam by the sword. The peaceful Muslims who believe in the righteousness of converting by the sword. They support and admire the jihad killers. The just don't personally want to do any killing.
To Muslims the world is divided into two distinct houses. Dar al Islam, the house of submission to Islam and Dar al Harb, the house of war which is everywhere that hasn't submitted to Islam. Muslims have a religious obligation to bring the world to Dar al Islam.