National Geographic reports that “the U.S. Senate’s failure Tuesday to approve Keystone XL won’t resolve the seemingly endless pipeline saga that has engulfed Barack Obama’s presidency.”  

“Looking ahead, here are six questions and answers about the pipeline’s fate.”

1. “Why has Keystone XL remained so controversial?”
2. “What’s holding up an Obama administration decision?”
3. “Will Obama really veto a bill to approve Keystone?”
4. “Does TransCanada face other state-level obstacles?”
5. “Aren’t other pipelines proposed to move oil sands crude?”
6. “Will falling oil prices decrease demand to produce and transport oil sands?”