A long time ago, every comment on YouTube was vitriol. It didn't matter what the video was, every single comment was pure poison. Today you can safely read the comments on videos that don't have political context. Of course anything political is going to be completely overrun with state level astroturfing, extremists, and mouth breathers. Occasionally I'll accidentally read the comments on something political, forgetting that comments should be off-limits for that video.
why are Canadian military aircraft flying in international waters off the coast of China
From the description of the video, should you care to read it:
Global News was on board the Canadian military aircraft reporting on the mission, which is part of Operation NEON, Canada’s contribution to helping enforce sanctions against North Korea, when the aggressive intercepts took place.
Sabre rattling. They're not going to engage. It's about intimidation. They want reactionaries in North America to sound the alarm and make the first (wrong) move first.
This is why kids don't run a country (except for America when they need a stooge). You need the brains god have a gnat to not start wars between superpowers.