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.
It's really a sad little pretzel of hell that we (supposedly) need to create economic incentives for every human on Earth to not squander their local resources for short term gain when it is in fact economic incentives that got that ball rolling downhill in the first place. But yeah, I guess we'll find a way to throw globalism and money at a problem created by globalism and money.
But it's important to recognize where capitalism fails (tragedy of the commons situations, negative externalities) and address those.
Something like this exists in the Amazon Fund. Unfortunately it seems like it has broken down lately:
https://www.reuters.com/article/us-brazil-environment-norway...
I think the state should take on that role, but there needs to be a strong inventive for them to want to protect it.
Maybe we should start fixing problems within our own borders first before resorting to fucking weapons.
It was amazing seeing the effect of political action on the satellite data: e.g. areas that were deemed okay (or not) to cut down were almost immediately protected (with lit borders to stop law-breakers) or destroyed.
If Brazil becomes a failed state, of course the Amazon will be destroyed. We know this due to the millions of examples of the ‘tragedy of the commons’.
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).