Commentary President Biden’s virtual meeting Tuesday with Russian President Vladimir Putin might be thought of as a final check-up before Russian troops invade Ukraine. Biden has displayed nothing but weakness since taking office. Even his threats of “consequences” sound weak. The president of Ukraine, Volodymyr Zelensky, sounded bolder than the U.S. president when he threatened to “derail” any invasion of his country by Russian forces. Look how different the world appears after Donald Trump left office. Biden ordered a precipitous withdrawal from Afghanistan and all the administration could do is brag about what an efficient job it did in moving so many troops out so quickly, despite the 13 U.S. service members killed in the last days and the translators and Americans left behind. China for the first time is building a naval base in the Atlantic Ocean, off the African coast. Beijing is also ratcheting up military flights over Taiwan and again threatening to invade …