Isn't the Keystone XL Pipeline in Our National Interest?

Won't it reduce our dependence on Middle Eastern oil? Won't somebody else develop the Alberta tar sands if the U.S. doesn't do it -- someone like China, perhaps?

I've been wrestling with many of these issues as I contemplate risking arrest as part of two weeks of sustained protest by leading environmentalists, climate scientists, and faith-based groups at the White House forth to pressure the Obama Administration to block the Keystone XL Pipeline. This pipeline project will connect Canadian tar sands -- containing the second largest and dirtiest oil reserves on the planet -- with the oil refineries in Texas.