Arabic to English Art/Literary Government / Politics Syria

Hi everyone,

I'm translating a story in which the narrator travels from Sweida to Damascus and describes what happens at all the checkpoints along the way.

Context:
كان المسافر یقطعها قبل الحرب بسیارته أو بالبولمان في غضون ساعة. بعد زرع الحواجز تطاولت الساعة إلى ساعات: حواجز للجیش ولجیش الدفاع الوطني وحواجز للّجان الشعبیة. كلّ حاجزٍ منها سلطةٌ عصماء لا تعترف بشرعیة السابقة أو اللاحقة.

I'm having trouble finding the right equivalent adjective in English as there isn't much information in the dictionaries. I think it means something like "untouchable/extremely powerful", but I want to check. I'm also unsure whether the author is being sarcastic or not - i.e. perhaps the author wants to say that if there are so many authoritative groups in the area, then how can they ALL think they are untouchable?

Thanks for your help!
Anam