President Biden on Thursday warned of the present threat to democracy in Europe and beyond as he marked 80 years since the American-led invasion of Nazi-occupied France on D-Day, saying in Normandy that "the struggle between a dictatorship and freedom is unending" while pledging that "we will not walk away" from Ukraine. "The price of unchecked tyranny is the blood of the young and the brave," Mr. Biden said. "In their generation, in their hour of trial, the allied forces of D-Day did their duty. Now the question for us is, in our hour of trial, will we do ours."...