In the narrow throat of the Strait of Hormuz, where a significant share of the world's oil passes each day, a tanker crew heard two unexplained explosions near the Omani coast on Thursday — and emerged, for now, unharmed. The incident is not isolated but part of a deepening pattern since regional conflict erupted in late February, one in which Iranian forces have increasingly shaped the terms of passage through waters the world depends upon. Diplomacy between Iran and Oman attempts to give formal structure to an informal reality, while environmental groups warn that the accumulation of insecur