Evan Vucci / AP President Obama has rejected the Keystone XL pipeline, killing the long-stalled project to bring oil from the Canadian tar sands to Texas. “The State Department has decided that the Keystone XL pipeline would not serve the national interests of the United States,” Obama said. “I agree.” The announcement, during which the president was flanked by John Kerry, his secretary of state, and Vice President Joe Biden, is the culmination of years of debate—much of it rancorous—over the Canadian company TransCanada’s proposed 1,661-mile pipeline.