You're reading: CBS News: US trains troops for front line in `hybrid war` with Russia

It was an ambush in a frozen pine forest. Russian-backed separatists surprised the group of Ukrainian soldiers. In the chaos, the Ukrainian forces took cover and fought back.

But they fired blanks. This time it was just an exercise, run by the U.S. military. But the Ukrainian soldiers taking part in the counter-attack drill will be headed to the real front line very soon.

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