Russia's invasion of Ukraine is a test for America: John Dickerson

President John Kennedy listed the challenges of the presidency this way: "Domestic policy can only defeat us; foreign policy can kill us." President Joe Biden faces both unpleasant presidential truths.  

But Russia's invasion of Ukraine isn't just a test of Joe Biden. It's a test of America, once a global champion of freedom and self-determination, whose presidents could rattle the Russians by merely testifying to those ideas out loud.

On June 12, 1987, President Ronald Reagan, speaking near the Berlin Wall, said, "We believe that freedom and security go together, that the advance of human liberty can only strengthen the cause of world peace. … Mr. Gorbachev, tear down this wall!"