"Eight former U.S. national security practitioners — the two of us, plus former U.S. representative to NATO Ivo Daalder, former undersecretary of defense Michèle Flournoy, former U.S. ambassador to Ukraine John Herbst, former deputy undersecretary of defense Jan Lodal, former NATO European commander James Stavridis and former U.S. European Command deputy commander Charles Wald — come together issuing following recommendations for immediate action. (releasing Monday report: “Preserving Ukraine’s Independence, Resisting Russian Aggression: What the United States and NATO Must Do.”) First, White House and Congress must commit serious money to Ukraine’s defense: $1 billion in military assistance this fiscal year,...