You have entire gold mining illegal operations with heavy machinery deep in the forest without any law enforcement to halt them. Murder of indigenous locals in clashes with illegal miners is also not uncommon. Similarly to coca farming in Colombia they simply relocate to another unknown location periodically.

Even assuming good faith from Brazilian law enforcement/military the remoteness and shear size of the rain forest makes it a huge challenge to enforce any rule of Law.

It seems there is some hope:

https://earthobservatory.nasa.gov/images/145988/tracking-ama...

> A (...) satellite-based system, DETER, went into operation in 2004 (...)

> “DETER completely changed the way rangers went about enforcement work,” said Rajão. Rather than doing random patrols and checking for permits, rangers would send squads of enforcement officers — with satellite images in hand — to investigate areas of recent, suspicious activity. That made it much easier to remove or apprehend equipment. The word spread among deforesters. The existence of DETER meant that environmental authorities would likely notice if large tracts of land were cleared, and fines and agents would follow soon enough.

You don’t necessarily need to enforcement at the whole region but at the perimeter where heavy machinery and cargo need to pass to reach customers. But since this comes with a big cost still UN should help out with enforcing such laws.