The countries that I grew up in are a melting pot of many nationalities living and working together in relative harmony. It is testament to the human desire (and necessity) to collaborate for the common good that obligates people to understand and respect different cultures, before putting into practice various coping techniques.
Language is the obvious main difference, but surprisingly has the least impact as most of the educated workforce speaks English. While making the effort to learn Arabic is rewarded with great affection from the locals, it is largely unnecessary. What can cause greater impediment is being unaware of the different nuances of communication needed when engaging with different audiences. There are enormous benefits to interactions between people of different faiths, backgrounds and experiences and I look upon my time in the Middle East with enormous affection. As expats we often expect people to adapt to our way of thinking and approaches to work and life, but we would be very well advised to embrace cultural differences for the benefit of all.
Above I outline some customs and etiquette to bear in mind when doing business in the Middle East.