The protests against President Aleksandar Vucic of Serbia had been growing in intensity and size when an unusual guest showed up in its capital this month to meet with the embattled European leader: Donald Trump Jr., the oldest son of…

The protests against President Aleksandar Vucic of Serbia had been growing in intensity and size when an unusual guest showed up in its capital this month to meet with the embattled European leader: Donald Trump Jr., the oldest son of…