Final answer:
After the Arab Spring, the overarching challenge faced by the Arab world was political instability, which arose from the power vacuums left by ousted leaders and was compounded by economic turmoil and social unrest.
Step-by-step explanation:
The Arab Spring of 2011 resulted in the toppling of several autocratic leaders across the Arab world. Following the overthrow of these leaders, the region faced several challenges, including political instability, economic hardship, sectarian conflicts, and social turmoil. However, the biggest challenge after overthrowing their leader varied by country, but political instability was a critical problem faced by many of these nations. This instability stemmed from the power vacuums created after long-serving dictators were deposed, which often led to fractious interim governments, coups, or prolonged periods of chaos. Countries like Libya have struggled with forming a stable central government, Egypt has seen a cycle of protests followed by military control, and Syria has been engulfed in a devastating civil war. Meanwhile, economic turmoil and social unrest continued to challenge these societies, with marginal improvements in some areas but continued strife in others.