The U.S. military last week released this photo of what it said was the seizure of a tanker in the North Atlantic. - Handout/U.S. European Command/Agence France-Presse/Getty Images For now, the official oil price is calm. But the U.S. attack on Venezuela is creating pressure on the shadowy market for sanctioned crude and its biggest customer: China. Brent, the main international benchmark, is trading around $63 a barrel and has risen less than $3 since President Nicolás Maduro was captured. Some addition ...