Israel's army chief said on Tuesday that Hezbollah's military chief was killed last year by his own commanders.

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Lt. Gen. Gadi Eisenkot said reports that Mustafa Amine Badreddine was killed by Hezbollah officers are in accordance to "intelligence we have." The incident "indicates the depth of the internal crisis within Hezbollah," and "the extent of the cruelty, complexity and tension between Hezbollah and its patron Iran."

He added that despite Hezbollah's fighting in Syria providing it with cumulative operational experience, it remains in crisis. "It is an internal crisis over what they are fighting fore, an economic crisis and a leadership crisis," he asserted. Eisenkot was speaking at an academic conference in Netanya.

Badreddine, one of Hezbollah's highest ranking military commanders, was killed in Syria in May last year. Initial reports attributed the attack to a covert Israeli operation, but signs suggested otherwise.

Badreddine was said to have assumed the position of his brother-in-law, Hezbollah commander Imad Moughniyeh, who died in a 2008 assassination in Damascus also attributed to Israel. However, some dispute his official status as the group's military leader, saying he was only in charge of its operations in Syria, as Hezbollah has never publicly named a successor for Moughniyeh, whose son Jihad was also killed in Syria in an attack said to be Israel's doing.

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A U.S. Department of the Treasury statement detailing sanctions against Badreddine had said he was assessed to be responsible for the group's military operations in Syria since 2011, and he had accompanied Hezbollah leader Sayyed Hassan Nasrallah during strategic coordination meetings with Assad in Damascus.

Eisenkot also hinted at the Israeli army's recent operational activity, which has generated tension with the Russian regime. He said, "Despite six years of war in Syria, we are managing to maintain a quiet border, and to prevent the growth in power of those who need not be strengthened with advanced weaponry." He added that the civil war in Syria involves not only risks but also "many opportunities for regional and international cooperation."

In his remarks, Eisenkot also stressed Iran's influence on Hezbollah and Hamas. "Iran is waging before us another campaign, a proxy war, and it is present both in Lebanon and in Syria with thousands of Shi'ite militiamen, as well as in Gaza," he said. The chief of staff contended that the "primary challenge" for the Israel Defense Forces is Hezbollah, which operates both in Lebanon and in Syria.

Mossad chief Yossi Cohen, however, said Iran poses Israel's foremost threat. Iran did not give up its nuclear ambitions, and it is trying to influence and shape the Middle East, said Cohen, also at the conference.

"As long as the Ayatollah regime exists, Iran will be the primary challenge for the security establishment, with or without the nuclear deal," he asserted.