WSJ's Jon Emont shows how a combination of environmental activists, the fires in Indonesian rainforests in 2015- that at one point emitted as much carbon as the US hurting investment in Indonesia- and action taken by the Indonesian government to limit deforestation, have led to cleaning up supply of palm oil through deforestation. Maps show the deforestation that took place before 2015 and between 2015-2021, in Borneo and Sumatra, islands in the Indonesian chain. Opaque supplier connections to plantations all over the country made it difficult to trace the supply of oil from suppliers such as Wanda, KPN and others to Unilever for Dove soap, Mondelez for cookies, and other users of palm oil. It was the concerted and persistent effort of Greenpeace, the Indonesian government and of the companies that made it possible to clean up the supply chain. In 2018-2021 palm oil production increased by only 1%, compared to 22% for the period 2015-2018.