In the last half decade, the United States, once a net importer of natural gas, is now on the threshold of becoming a major exporter of liquefied natural gas (LNG). In the early part of the 21st century, companies began building LNG import terminals in advance of an expected decline in natural gas production.What was once seen as a strong investment began to sour as unconventional natural gas producers started to unlock the vast amounts of shale gas reserves in North America. While the first of these shale plays to...