As it turns out, US is indirectly funding the research and creation of the ever-so-controversial nuclear reactors. These reactors, stated to be with a peaceful purpose by the Iranian govt., are suspected to start producing plutonium for military purposes.

The US finance is indirect, because it is funneled through the Russian scientists, working in Iran. After the cold war, Russian scientists were employed by the US, to prevent the scientists starting work for rogue countries.

I further remind, that even during the WWII, several US businessman (maybe told to do so, maybe not), supported financially all sides right before the war. 

YouTube video of CNN, revealing the financing scheme.

Guardian article: How Bush's grandfather helped Hitler's rise to power

 

US funding Iranian nukes