What does it mean?
Her colleague’s accusation "came on the heels of a call "summoning Khulood to the local militia headquarters. “That’s when I finally saw there was no chance for me in Iraq, that if I tried any

Question

Answer

“(hard) on the heels of something” means “close behind something/soon after something”.
So the sentence could be written as “Her colleague’s accusation came soon after a call summoning Khulood to the local militia headquarters.”

Answer

"came on the heels of" means soon right after :)