As the Obama administration puts off once again any decision on authorizing the Keystone XL pipeline, there are whispers of another intriguing possibility. If the U.S. government fails to approve the pipeline soon or rejects it outright, the Canadians may challenge the delay or rejection under the provisions of the North American Free Trade Agreement (NAFTA)signed by both countries. This move opens up a politically attractive option not previously available to the Obama administration, something I’ll discuss below.