The violence throughout the Muslim world is about a number of issues. These are all part of the same ideological war. The common denominator for me is the repeated suicide attack.
Suicide has always been a part of warfare. However, repeatedly organized suicide attacks have only been seen on one prior occasion throughout all of human history. This was Japan in the 1940's.
Although markedly different from today (All wars are unique) many similarities exist that are worrisome. The brutality exhibited in both occurrences is one symptom of the ideological persuasion necessary to supply an organized campaign of repeated suicide attack with volunteers. After all, the suppression of the most basic instinct of all living things would require extensive training of the minds of many. To support an ongoing campaign of repeated suicide requires far more people who believe in the concept than just those who actually carry out the attacks. In Japan, the concept was culturally based. I believe that it is today and this is the main reason as to why the rare occurrence of repeated suicide attack is so relatively common throughout the Muslim world.