ICN

One of the biggest unknowns in the unfolding Keystone XL debate is the role the U.S. Environmental Protection Agency might play.

Because the Canada-to-Nebraska oil pipeline crosses an international border, the State Department, not the EPA, will decide whether to give the project the federal permit it needs. But the EPA will weigh in during the review, and its opinion will carry new weight now that the Obama administration has vowed to make climate change a national priority.