The most prudent policy would never knowingly do business with any muslim entity, country or person.
I work in an international business and work with several Mohammedans. One guy seems religious but genuinely kind, despite his religion. Another guy seems to be non-practicing, and the woman always looks at me like she wants to rip my throat out.
I have one policy for predominantly black neighborhoods and Muslim countries: STAY AWAY!!
The Germans bombed my country twice, the IRA killed my cousin. Do I hate Germans and Irish?. Quite the opposite.