As allies go, Venezuela is a relatively cheap one for Russia. But the potential returns on Moscow’s investment there could be priceless. In exchange for modest loans and bailouts over the past decade, Russia now owns significant parts of at least five oil fields in Venezuela, which holds the world’s largest reserves, along with 30 years’ worth of future output from two Caribbean natural-gas fields. Venezuela also has signed over 49.9 percent of Citgo, its wholly owned company in the United States — including three Gulf Coast refineries and a countrywide web of pipelines — as collateral to Russia’s state-owned Rosneft oil behemoth for a reported $1.5 billion in desperately needed cash. Russian advisers are inside the Venezuelan government, helping direct the course of President Nicolás Maduro’s attempts […]