When Chevron employees visit former oil fields in Ecuador, they do so escorted by armed guards. The oil company is deeply enveloped in controversy there over drilling projects started in the 1960s by Texaco, which it acquired in 2001. Villagers say the sites were never fully cleaned up and that pollution, which over decades has leached into groundwater and streams, is causing cancer deaths. In lawsuits, villagers are seeking as much as $3 billion. Chevron is fighting back, lobbying Washington to pressure Ecuador into trying to resolve the conflict, but there’s evidence that this fight may only be getting started.