Isaac Herzog, the leader of the Israeli leftist labor party (whom President Obama backed against Benjamin Netanyahu in the 2015 Israeli election), is sounding the alarm over the Iran nuclear deal, which he predicts will bring "chaos" to the region.

In December, Herzog expressed great "trust" in the Obama administration to hammer out a "good deal" with Iran. But now that the terms of the deal have been finalized, Herzog has dramatically changed his tune, warning that the massive concessions to Iran "will unleash a lion from the cage."

Herzog made the comments during a call to The Atlantic's Jeffrey Goldberg Tuesday, which Goldberg notes sounded "very different" than their December conversation:

The deal just finalized in Vienna, he said, "will unleash a lion from the cage, it will have a direct influence over the balance of power in our region, it’s going to affect our borders, and it will affect the safety of my children."

Iran, he said, is an “empire of evil and hate that spreads terror across the region,” adding that, under the terms of the deal, Iran "will become a nuclear-threshold state in a decade or so." Iran will take its post-sanctions windfall, he said, and use the funds to supply more rockets to Hezbollah in Lebanon, more ammunition to Hamas in Gaza, and "generally increase the worst type of activities that they’ve been doing."

Herzog, who lost a race for the prime ministership in March to the Likud’s Benjamin Netanyahu, had mainly kind words for his archrival, and he even invoked an expression popularized by Netanyahu’s ideological guide, the founding father of right-wing Zionist revisionism, Ze’ev Jabotinsky, to describe what he sees as Israel’s next, necessary step: "We have to build an iron wall to protect Israel. There are clear risks to Israel’s security in this deal."

Herzog's alarm over the deal mirrors that of a majority of Israelis. A new poll found that over two-thirds of Israelis believe the deal only makes the likelihood of Iran obtaining nuclear weapons more likely, while almost half now support a unilateral strike against Iran. AFP reports:

Asked "Do you support independent military action by Israel against Iran if such action is needed to prevent Iran from obtaining a nuclear weapon?" 47 percent said yes, 35 percent said no and 18 percent expressed no opinion.

Asked: "In your view, does the agreement that was signed bring Iran closer to obtaining a nuclear weapons capability?" 71 percent said yes.