Not all muslims are terrorists, but most terrorists are muslims.
Great Britain - Love it or leave it.
Unfortunately, a large section of muslims take this to mean that the Koran, being of god, shall prevail over all laws of man. For example, they believe that democracy is the law of people, not god, and so it is not for the devout muslim. Further, the contents of the Koran (evolved several hundred years back in a nomadic, warlike, women-suppressing community) are believed to be equally valid now.
In countries where islam is dominant, there is war between factions or between secularists and islamists. In the countries where they are minorities, they have problems with the majority community (no matter which community this is--look at Mindanao, where one of the most pacific people, the Philippinos, are finding it difficult to coexist because of the Abu Salem group).