Putin did business with Obama (tell Vlad I'll have more flexibility after the election) as did Hillary as Obama's SOS
https://www.nytimes.com/2015/04/24/us/cash-flowed-to-clinton-foundation-as-russians-pressed-for-control-of-uranium-company.html
And he'll do business with Biden now. The tough talk is just for show, although Putin probably does think Biden is a joke.