Because of the work of generations, because we've stood together in a great alliance, because people across this continent have forged a European Union dedicated to cooperation and peace, we have made historic progress toward the vision we share -- a Europe that is whole and free and at peace. And yet, as we gather here today, we know that this vision is threatened by Russia's aggression against Ukraine. It is a brazen assault on the territorial integrity of Ukraine -- a sovereign and independent European nation. It challenges that most basic of principles of our international system -- that borders cannot be redrawn at the barrel of a gun; that nations have the right to determine their own future.