Islam exists peacefully and quietly in such circumstances only until it is in a position of strength to change the circumstances and conquer: to take control of the host. Islam always seeks to become a state-within-a-state wherever it makes inroads, with the ultimate goal of replacing the entire law and entire civilization of any nation with Sharia law, and with the Quran as the only acceptable constitution. In short, Islam fully intends for all nations to become Islamic nations.
That is precisely what Saudi Arabia is: the pinnacle of Islamic societies. The Quran is its only constitution. Sharia is its only law. Islam is its only acceptable religion. That is not Radical Islam; that is the pure orthodoxy of Literal Islam. That is what Islam wants to enforce upon every nation, every culture in the world, by any means, by any strategy, by any tactic. Those methods of fighting include willful deception, infiltration, terror, violence, propaganda, psychological warfare, and demographic saturation.