An influence campaign has relied on allies of the president, including Rudolph W. Giuliani, to cast a Serbian politician as a victim of political persecution.
Rudolph W. Giuliani, the former New York City mayor, with Milorad Dodik, center, the leader of Republika Srpska, a Serb-controlled region of Bosnia and Herzegovina, in February.
The proposed transaction, stemming from relationships that started while his father was vice president and involving a Chinese partner, underscores the extent of Mr. Biden’s questionable business dealings abroad.