In his latest address at a major nuclear industry event, Russian President Vladimir Putin praised veteran scientists for building Russia’s powerful “nuclear shield” and pioneering the peaceful use of atomic energy. At the same time, Donald Trump issued veiled warnings of his own, hinting that it’s “hard to win a war without striking the invader.” Tensions escalated further after reports that Russian missiles struck a U.S.-owned factory in Ukraine, where hundreds of civilians were working. Watch the video for more.