When President Biden said he was dropping his reelection bid, the sudden upheaval in U.S. politics came as a blow for many in the Russian elite who closely track relations between Moscow and the West. Biden's withdrawal in favor of Vice President Harris has upended a race that the Kremlin and its backers believed Donald Trump could win, creating "a window of opportunity" to settle the war in Ukraine on Russia's aggressive, expansionist terms, according to analysts and current and former Russian officials.