The gulf monarchies don't have any military. All they have is mercenaries. Pretend-troops. Exaggerated of course, but close to the truth.
They don't trust their own people with weapons because they could overthrow them. Their military power relies solely on allies, especially the US.
You say it's unrealistic for them to expect the world to keep their front porch clean, but that's exactly how it worked so far. Or at least the others didn't fuck around. And we currently see the effect when "the world" (really just two countries) doesn't do their part anymore. The US also very much needs their oil. The oil price rises everywhere, including the US.
No long lasting fear. But at the age of 10 I read the second Harry Potter book, and I was so afraid during the second half of the book I read through it in a single session, in bed at night.
At the time it was the longest and most intense reading session ever.