For this answer, all the Qiang tribe leaders felt the same disbelief, but after accepting this reality and reflecting, they realized every Qiang-Han conflict seemed never to be provoked by the tribes that made treaties with the Han Dynasty.
To exaggerate a bit, those tribes that formed treaties with the Han, upon noticing Qiang-Han tensions, even tried to mediate as much as possible, but ultimately it was like drawing water with a basket, ending in vain.
The tension between the Qiang tribes and the Han Dynasty was so taut that the slightest disturbance would snap it, inevitably leading both sides to war.
The reason why those tribes with treaties didn't first clash with the Han Dynasty was rather simple; for these initial tribes that pledged allegiance, there was a need to set an example to inspire confidence in future followers, so it was impossible to act rashly, and thus conflict was naturally avoided.
