Under threat from a TransCanada lawsuit, the U.S. government said it was confident the decision made on the Keystone XL oil pipeline was in line with the law. The pipeline company this week said it filed a lawsuit in a federal court in Houston challenging President Barack Obama ‘s decision on Keystone XL and was reviewing possible additional claims under the North American Free Trade Agreement. Obama rejected the permit for the pipeline proposed in 2008 largely on environmental grounds. Keystone XL was meant to carry a heavier grade of crude oil from Alberta that some advocacy groups said posed a greater risk than other kinds. […]