evidence: Obama’s Russia policy, including his embrace of the doctrine of Kremlin escalation dominance, has continued to shape U.S. policy during the Trump and Biden administrations. Although Donald Trump behaved badly toward Ukraine by trying to enlist Kyiv in his efforts to weaken presidential rival Joe Biden, he greenlighted the shipment of Javelin anti-tank weapons in 2017 and 2019. Nonetheless, years of fierce debate merely over sending Javelins stifled discussion of other weapons needed by Ukraine, including air and missile defense, battle tanks, fighter jets, and long-range missiles. These could have made Ukraine more secure before 2022, and some of them are still not in Ukraine’s arsenal today. To his credit, Biden advocated arming Ukraine with defensive weapons when he was vice president under Obama. But when he became president himself, Biden brought many of the architects of Obama’s timid approach to Russia back into the government. As a result of their influence, from the moment in the fall of 2021 when the U.S. government knew Putin was planning to invade to the start of the invasion on Feb. 24, 2022, the United States lost a crucial window in which to provide Ukraine significant new weapons and the training to use them. Instead of much-needed howitzers, tanks, multiple-launch rocket systems (such as HIMARS), and heavy ordnance, Washington doled out modest assistance enabling not much more than partisan resistance.