On Sept. 9, Russia violated Polish airspace with multiple drones. Four days later, they menaced Romania with a similar incursion. Since then, we’ve seen Russian fighter jets in Estonian skies and unidentified drones above airports in Oslo and Copenhagen, all while Moscow is escalating bombings of Ukrainian civilians and infrastructure. These intrusions should be a wake-up call for Europe and the free world. U.S. President Donald Trump is right to argue that Europe’s continued energy purchases