As plunging oil prices signal broad market optimism following an initial deal between the United States and Iran, attention has turned to whether Chinese firms sanctioned for Iran-related business will see immediate relief, though analysts remain cautious. “New purchases of Iranian oil ostensibly wouldn’t be subject to fresh sanctions, but at the same time, I imagine we won’t see a rush to lift existing sanctions on Chinese importers of Iranian oil,” said Lynn Song, chief economist for Greater...