Sensing that his blue team had been detected by the red enemy, Lieutenant Li Juntang decided to charge.

His 13-man squad was only 250 meters from the enemy's frontier guarded by just seven soldiers. But as they closed on the enemy, Li's men found themselves confronted by an enemy reinforcement and had to backtrack. Half of his men were captured but Li himself managed to escape.

The maneuvers were part of a military exercise organized by the Nanjing Military Area Command, featuring the nation's first mock enemy troop, the "Blue Army", founded in 1987.

For the first six months of the army year, "Blue Army" soldiers perform the same duties and undergo the same training as every other soldier in the People's Liberation Army (PLA), the only difference being that they have to finish the whole year's training in six months. In the second semester,their status changes radically.

They move into remote mountains, put on special uniforms and badges, speak another language, follow a different schedule, and prepare to attack their former comrades.

"We aim to be as like enemy troops as possible," said Huang Baohong, commander of the "Blue Army".

Li, 31, said he was upset when he was assigned to the troop in 2001, right after his graduation from the military academy.

"I couldn't understand at that time why I had been chosen to be one of the 'enemy force', since I had outperformed most of my peers in terms of my military and academic performance," Li said.

After talking to military psychologists, he developed a new understanding of his role.

"Our troop helps to create a mock war environment, and this will improve the overall battle effectiveness of the army. If the 'Blue' guys get stronger, then the 'Reds' have to improve too," he said.

He is now accustomed to his new role and has distinguished himself by capturing some "Red Army" chiefs during wargame exercises.

Armed with top-end weapons, including newly-upgraded tanks,the Blue troops are expected to lift skill levels in the whole army.

Major Luo Chuanquan said his 8-year-old son was initially very confused and depressed when he discovered that his father was an "enemy" of the PLA.

"But now he understands and admires what I do," said Luo, with a beam of pleasure. Enditem