For years, the Organization of Petroleum Exporting Countries has exasperated Western governments by acting as a cartel to control oil production. Now, the West may have a new foe: Gas OPEC. Yesterday, Russia, Iran and Qatar, the world's three leading natural gas producers, said that they were forming a "big gas troika" that could become a permanent body. It's not clear what role the group will have; Alexei Miller, chief executive officer of Russian gas monopoly Gazprom, said the body would meet up to four times a year to discuss pricing issues. However, Iranian Oil Minister Gholamhossein Nozari said he...