> It’s an interesting thought experiment as to what it would take for the world to force protection with an external military force (e.g. this might be the only solution, but the chances of it happening are zero).
Brazil would never tolerate that, nor should they.
On the other hand if you want to buy huge tracts of the Amazon and pay private security forces to protect it, that's doable.
Better though would be to make it in Brazil's interest to protect the Amazon. We all benefit from it being intact, so we should all chip in to create an economic incentive for the county of Brazil to maintain it.