Open: This is Face the Nation, December 18

Just weeks before President-elect Donald Trump is set to take office, “Face the Nation” goes in-depth on foreign policy and national security. We talk to Dr. Henry Kissinger about how Trump’s unpredictable style could be an asset, Tom Donilon about global challenges facing the president and Kellyanne Conway about President Obama’s response to reports of Russian hacks. Plus: A look back at the Obama presidency — and a discussion on the continued extremist threat.