ISTANBUL — The Islamic State uses terror to force obedience and frighten enemies. It has seized territory, destroyed antiquities, slaughtered minorities, forced women into sexual slavery and turned children into killers.

But its officials are apparently resistant to bribes, and in that way, at least, it has outdone the corrupt Syrian and Iraqi governments it routed, residents and experts say.

“You can travel from Raqqa to Mosul, and no one will dare to stop you even if you carry $1 million,” said Bilal, who lives in Raqqa, the Islamic State’s de facto capital in Syria, and, out of fear, insisted on being identified only by his first name. “No one would dare to take even one dollar.”

The Islamic State, also known as ISIS, ISIL and Daesh, initially functioned solely as a terrorist organization, if one more coldblooded even than Al Qaeda. Then it went on to seize land.