I for one am not at all surprised that this took place.  If anyone watches/reads the news and current events globally they would know that it was just a matter of time until something like this happened.  Also it doesn't hurt to know a bit of history about the region and specifically the religion of Islam.  Here are a couple of topics that might help some understand what exactly drives these people.

 

Salafi

Wahhabism

 

Quote: 

The <b>Salafi movement</b> or <b>Salafist movement</b> is an ultra-conservative orthodox movement within Sunni Islam that references the doctrine known as <b>Salafism</b>. The doctrine can be summed up as taking "a <a class="" href='https://en.wikipedia.org/wiki/Fundamentalist' title="Fundamentalist">fundamentalist</a> approach to Islam, emulating the Prophet Muhammad and his earliest followers—al-salaf al-salih, the 'pious forefathers'...They reject religious innovation, or bida, and support the implementation of 

sharia
 (Islamic law).

"^[1] The movement is often divided into three categories: the largest group are the purists (or quietists), who avoid politics; the second largest group are the activists, who get involved in politics; the smallest group are the jihadists, who form a tiny (yet infamous) minority.^[1]

<p style="color:rgb(37,37,37);font-familyans-serif;">The Salafi movement is often described as being synonymous with Wahhabism, but Salafists consider the term "Wahhabi" derogatory.^[2] At other times, Salafism has been described as a hybrid of Wahhabism and other post-1960s movements.^[3] Salafism has become associated with 
<a class="" href='https://en.wiktionary.org/wiki/literalist' title="wikt:literalist">literalist
</a>, 
<a class="" href='https://en.wiktionary.org/wiki/legalism' title="wikt:legalism">strict
</a> and 
<a class="" href='https://en.wiktionary.org/wiki/puritanical' title="wikt:puritanical">puritanical
</a> approaches to Islam and – particularly in the 
West
 – with the 
<a class="" href='https://en.wikipedia.org/wiki/Salafist_jihadism' title="Salafist jihadism">Salafi jihadists
</a>, who espouse 
<a class="" href='https://en.wikipedia.org/wiki/Offensive_jihad' title="Offensive jihad">offensive jihad
</a> as a legitimate expression of Islam against those they deem to be enemies of Islam.
^[4]

<p style="color:rgb(37,37,37);font-familyans-serif;">In legal matters, Salafis are divided between those who, in the name of independent legal judgement (<i>ijtihad</i>), reject strict adherence (<i>taqlid</i>) to the four schools of law (<i><a class="" href='https://en.wikipedia.org/wiki/Madhahib' title="Madhahib">madhahib</a></i>) and others who remain faithful to these.

 

Also, let's make a few things clear.

 

1.  Arab is an ethnicity, not a religion.  Not all Arabs practice Islam.

2.  Islam is a religion and is practiced world wide by people of different races/nationalities.

3.  Not all people that practice Islam are Salafi or Whahhabism followers.

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