US Secretary of State Marco Rubio warned on Wednesday of a “real” risk of the Ukraine war escalating, as Kiev showcases its ability to strike deep inside Russian territory. The remarks came after Ukrainian drones struck energy infrastructure in Russia’s second largest city, St. Petersburg, an attack Kyiv called retaliation for a mass wave of Russian strikes on Tuesday that killed at least 23 people. JOIN US ON TELEGRAM Follow our coverage of the war on the @Kyivpost_official . “ Ukraine has