Why did Riyadh join US strikes on Tehran's allies in Iraq?

Summary

Saudi Arabia joined the United States for the first time in launching air strikes against Iran-backed militias in Iraq on Wednesday, marking a significant shift in the kingdom's regional posture after months of restraint. While Riyadh insists it was acting in self-defence, the operation raises questions about whether the kingdom is abandoning its cautious approach towards Tehran – or simply sending a warning.