Five months after their shock offensive into Russia, Ukrainian troops are bloodied and demoralised by the rising risk of defeat in Kursk, a region some want to hold at all costs while others question the value of having gone in at all. Battles are so intense that some Ukrainian commanders can't evacuate the dead. Communication lags and poorly timed tactics have cost lives, and troops have little way to counterattack, seven front-line soldiers and commanders told The Associated Press on condition of anonymity so they could discuss sensitive operations. Since being caught unaware by the lightning Ukrainian incursion, Russia has amassed more than 50,000 troops in the region, including some from its ally North Korea. Precise numbers are hard to obtain, but Moscow's counterattack has killed and wounded thousands and the overstretched Ukrainians have lost more then 40% of the 984 square kilometers (380 square miles) of Kursk they seized in August. Its full-scale invasion three years ago .