1) Ashley Parker and Ellen Nakashima, “How Russia’s aggression in Ukraine in 2014 and 2015 is shaping Biden’s actions today; Biden, as Obama’s point man on Ukraine, wanted to ship more lethal weapons to the country but was overruled by his boss,”:New York Times, March 21, 2022 (3:00 am EDT)
2) Brian Naylor, “Biden will lay out in a call with Putin the U.S. response if Russia invades Ukraine,” NPR, December 6, 2021 (updated 9:16 pm ET):