By David Lawder WASHINGTON (Reuters) – U.S. President Joe Biden’s warning of “consequences” for any aid China may give to Russia’s Ukraine war effort could force Chinese President Xi Jinping to choose between a longstanding lucrative trade relationship with the West and a growing strategic partnership with Moscow. Based on trade flows alone, Beijing has a lot at stake following Biden’s nearly two-hour video call with Xi on Friday, with the White House confirming that sanctions on China were an option. Despite growing trade ties to Southeast Asia and an economy that is less dependent on trade o…