Iran announced yesterday that it has tested a new weapon capable of sinking ships nearly 200 miles away, and reiterated threats to close a strategic waterway at the mouth of the Persian Gulf if attacked. Up to 40 percent of the world's oil passes through the Strait of Hormuz, a narrow passage along Iran's southern coast. Tehran has warned it could shut down tanker traffic there if attacked, a move likely to send oil prices skyrocketing.