On August 25, Juche 49 (1960), he started his guidance over the revolutionary armed forces with the inspection of the Seoul Ryu Kyong Su Guards 105th Tank Division of the Korean People's Army (KPA).

In his historic talk "'Let Us Defend with Our Very Lives the Party Central Committee Headed by the Respected Comrade Kim Il Sung!' - This Slogan Should Be Held Higher by the People's Army" made on the day, he clarified that it is the basic mission and the core of the glorious tradition of struggle of the KPA to devotedly defend the Party and the leader.

In his famous works published in the 1960s he clearly indicated the principled issues arising in comprehensively establishing the leadership system of the Party in the People's Army.

In the 1970s and 1980s, he made public a lots of works such as "The People's Army Should Stand in the Vanguard in the Efforts for Accomplishing the Cause of Our Party", "Let Us Model the Entire Army on Kimilsungism" and "Let Us Further Strengthen and Develop the People's Army into the Army of the Great Leader and the Army of the Party". In those works he clarified the most correct programme for army building to develop the People's Army into the army of the leader and the Party forever, including the tasks and ways for preparing all the service personnel as Kimilsungists and the general orientation and basic object for building the revolutionary armed forces.

In the 1990s he advanced the original idea on Songun politics and published several works dealing with the tasks and ways for developing the People's Army into a-match-for-a-hundred revolutionary armed forces and matchless army while consistently holding fast to the Party's idea and line of attaching importance to military affairs.

In the 2000s, he made public such works as "The People's Army Must Be a Model and Play the Role of Pace-setter for Society in All Aspects" and "On Continuing to Direct Great Effort into Strengthening the People's Army, Holding High the Banner of Songun". Thus he made sure that the KPA played its role as the first standard-bearer and shock brigade in all fields of the revolution and construction as required by the Songun era, and implanted in the minds of the people and service personnel the philosophical principle that peace and socialism depend on the matchless arms.

The great celebrated works on strengthening the revolutionary forces published by Kim Jong Il for over 50 years are shining as immortal ones in the history of army building of Juche as they are precious guidelines to be consistently held fast to in developing the KPA into an invincible elite revolutionary army.