North Korean intervention could cost China South Korean neutrality

Would North Korea be likely to join China in a future war?

Possibly. In this scenario, North Korean intervention could burden China and make it much harder to keep South Korea neutral.

In this 2020 scenario, North Korea might join China because the regime depended heavily on Chinese support. Its intervention could create as many problems for Beijing as it solved. Chinese planners would have to sustain North Korea while losing any realistic chance of South Korean neutrality. The powerful South Korean Navy could then become another serious maritime opponent in the theater.