In the view of the new Mossad Director Yossi Cohen, Iran has become the most substantial threat facing Israel since signing a nuclear accord with the six powers. Tehran still calls for Israel’s annihilation regardless, while upgrading its military capabilities and deepening its grip on the region, he said. “The tools Iran uses to achieve its ends are tentacles of terror.”  Cohen takes over from Tamir Pardo who ends his five-year term as head of the Mossad. The new director is a veteran of Israel's external security service, having risen through the ranks after joining the Mossad at the age of 22. More recently, he served as national security adviser to the prime minister, who attended the changeover ceremony Wednesday.