KABUL — Col. Samuel Whitehurst had been consumed with work in the last days of his brigade's nine-month deployment in eastern Afghanistan when alarming news about his former battleground in northern Iraq began to reach him.
Whitehurst fired off an e-mail to the mayor of the Iraqi city of Samarra, who had become a close friend, saying he was thinking of him. Days after a band of Islamic militants took over Mosul and several towns in the north in early June, he got terrible news: Col. Gayath Sami, the Iraqi officer Whitehurst had groomed to run Samarra's security command center, had been slain in the fighting.
"To find out that he had been killed," said Whitehurst, who commands the 3rd Brigade Combat Team of the 10th Mountain Division, deployed in Paktia province. "Those are the things I worry about — the friends I met there and what's going to happen to them."