Kim Jong Il in his lifetime gave priority to preparing servicepersons politically and ideologically in beefing up the revolutionary armed forces.

Whenever he inspected the military units, he went round the monuments to field guidance of President Kim Il Sung, monuments inscribed with his on-site instructions and rooms dedicated to the history of the units, putting the ideological education among servicepersons before anything else.

His energetic guidance led servicepersons' mental world to a high level. With the spirit of devotedly defending the leader, Kil Yong Jo drove his burning plane into the sea and KPA soldiers on Mujae Hill threw themselves into the fire to protect slogan-bearing trees from burning. The spirit turned out many heroes, including those who covered with their bodies grenades on the verge of explosion to rescue fellow soldiers.

Kim Jong Il also made big efforts to increase the combat capabilities of the KPA.

He saw to it that all KPA commanding officers were capable of working out any operations in a creditable way. And he made ceaseless inspection tours of military units throughout the country, in disregard of weather conditions, to encourage the servicepersons in intensive military training under the slogan "Training Is Also a Battle!"

Now the KPA has turned into an invincible army with mighty offensive and defensive means.

In December Juche 83 (1994), a KPA soldier gunned down a U.S. army helicopter that intruded into the DPRK's territorial air and in July 1997, a KPA artillery unit made a clean sweep of enemies' positions, when provoked by them in the Demilitarized Zone along the Military Demarcation Line. In November 2010 when the south Korean puppet army began shelling towards the territorial waters of the DPRK around the Yonphyong Island, the KPA launched a prompt and powerful, retaliatory strike against them.