Hi there

I came across this sentence while reading a news article of(what other prepositions can I use here?) Reuters. Is the sentence correct? the commas? Why is there a comma before may and why is not there a comma before threatening?

"Western allies have poured billions of dollars in aid into Pakistan, worried that growing public anger over corruption, poverty and energy shortages, may boost recruitment to Islamist militant groups threatening to destabilise Pakistan and beyond."

Regards