Juche or self-reliance is what Koreans lives by. It is a poignant ideology, except it cuts you off from the potential frenemies who feel threatened by the solitary stance it takes.
From the inside, North Korea wants to prove to its people it can remain defiantly independent and fiercely nationalistic without anyone’s aid or patronage. Soviet Union dropped aid support under Boris Yeltsin in the 90s. China is its sole friend and trade partner (the friendship today is on shaky ground owing to the threat of nuclear war).
The DPRK has no friends, yet an army of comrades. That explains its permanent state of militarism and memorials built to commemorate the war heroes.