Ukraine Update: The Rebels Are on the Defensive

Since a cease-fire expired in early July, Ukrainian security forces have made real gains on the battlefield, siphoning off territory from pro-Russian separatists and forcing them to go on the defensive. With a concert of air power, artillery and thrusts that combine infantry and armor, Ukrainian forces have advanced along three axes. As military operations move farther east toward Russia, however, the operation will face more stubborn and capable resistance — as long as Russia continues to support the militants.