In 2006, Ukrainian Prosecutor General Viktor Shokin, in his investigation of corruption involving natural gas company Burisma Holding, identified Hunter Biden as the recipient of over $3,000,000 from the company.
Not wanting this corruption exposed, Joe Biden swung into action, using US loan guarantees as hostage while demanding Skokin be fired.
This video shows Biden bragging about his actions in this matter.
You can find videos and telephone calls of Shokin, and how Biden worked on him and the country, on this channel.