London's socialist mayor signed an agreement Tuesday with Venezuela's state-owned oil company to provide discounted oil for the city's iconic red buses, praising the idea as the brainstorm of the country's leftist leader, Hugo Chavez. Ken Livingstone — a committed socialist known locally as "Red Ken" — met with Chavez last year at City Hall to discuss the deal to provide cheap oil to London in exchange for advice on urban planning in Caracas, the Venezuelan capital. Venezuela has signed similar agreements with cities in several other countries, including the United States. Critics call it "oil diplomacy" — and say...