You do know that the USA is also a signatory to the Christchurch Call?

It agreed to (among other things):

"Counter the drivers of terrorism and violent extremism by strengthening the resilience and inclusiveness of our societies to enable them to resist terrorist and violent extremist ideologies, including through education, building media literacy to help counter distorted terrorist and violent extremist narratives, and the fight against inequality."

Law works by mutual agreement. This is how our global system hangs together. Just because this is being spearheaded by an Australian process, doesn't make it apply only to Australia.

This same process happens every day across the world. The only difference here is that the person on the other end is pretending that this is about free speech.

Where's the hue and cry from all the other platforms who just took it down? Are they perhaps more aware of how this works?

Edit:

Perhaps this is stating the obvious, but the Christchurch Call came into existence after a terrorist massacre was livestreamed from Christchurch. It's not a random website, it's the New Zealand government response to that event.

Mutual obligations, agreements and treaties are what bind us together legally. Within the legal framework in Australia, CSE and terrorist video are the same, both considered Class 1. My reference to CSE was deliberate. From an Australian perspective they're one and the same. Different countries can argue that they're not, but that process is ongoing.

Finally, courts making decisions that affect others happens all the time. Just look at the abortion mess currently playing out across courts all over the USA, not just from the SCOTUS down, but between states as well.

This is the very same thing, it's just happens to be a country border, not a state one.

Edit 2:

It's not like the USA hasn't done this to others either. Right now it's making laws to force a company in another country to sell an asset, TicTok.