MUNICH — When Russia invaded Ukraine three years ago, the United States helped whip Europe into a staunchly unified response. Now U.S. leaders may be splitting Europe into pieces as President Donald Trump seeks to end the war, European leaders and policymakers say.Vice President JD Vance and other top administration officials made their European debut last week, slashing their way through a continent of allies as they embraced far-right leaders, demanded access to mineral wealth and offered sympathy to the views of Russian President Vladimir Putin.By the end of the week, European leaders found themselves potentially cut out of peace...