The nuclear deal with Iran has emboldened Tehran to become increasingly aggressive in the Middle East, Israeli Prime Minister Benjamin Netanyahu said Sunday, warning that Iran should “not test Israel’s resolve” as he showed off what he said was part of an Iranian drone downed by Israel after it entered its airspace.

Netanyahu said of Iran that if the U.S. decides to scrap the 2015 nuclear deal, which he has long opposed, “I think they’ll do nothing.”

But Iranian Foreign Minister Mohammad Javad Zarif, appearing two hours later at the same Munich Security Conference, fired back that Netanyahu’s comment was “delusional thinking.”

“I can assure that if Iran’s interests are not secured, Iran will respond, will respond seriously. And I believe it would be a response that means people would be sorry for taking the erroneous action they did,” he said.

U.S. President Donald Trump has expressed deep skepticism about the Iran nuclear deal that lifted sanctions against the country. He extended sanctions waivers in January but said he would not do so again when they come up for renewal in May unless his concerns are addressed.

Former U.S. Secretary of State John Kerry, a main architect of the nuclear deal, said it was “absolutely critical” to ensure it survives.

“We know what the world looks like without the Iran nuclear agreement,” he said Sunday, speaking at the same conference. “It’s not a better place.”

If the U.S. abandons the current nuclear deal it’s unlikely Iran would consider a new one, Kerry said.

“The problem is the waters have been muddied because of this credibility issue about America’s willingness to live up to any deal,” he said.

Kerry dismissed Netanyahu’s contention that Iran would be on its way to having a nuclear arsenal in 10 years, saying “that’s fundamentally not accurate.”

Saudi Foreign Minister Adel al-Jubeir weighed in, saying the Iran nuclear deal “has flaws that need to be fixed.” He said that, among other things, the inspection system needs to be more intrusive.

“The world has to extract a price from Iran for its aggressive behavior,” he added.

Netanyahu told world leaders, diplomats and defense officials at the conference that the deal was similar to the infamous 1938 “Munich Agreement” that Western powers signed with Adolf Hitler in an attempt to stave off war in Europe, which became synonymous with appeasement.

“The concessions to Hitler only emboldened the Nazi regime,” he said. “Rather than choosing a path that might have prevented war… those well-intentioned leaders made a wider war inevitable and far more costly.”

Similarly, he said, the Iranian nuclear agreement has “unleashed a dangerous Iranian tiger in our region and beyond.”

Declaring that Iran’s “brazenness hit new highs,” he theatrically held up a fragment of what he said was an Iranian drone shot down last week by Israel in Israeli airspace and challenged Zarif.

“Mr. Zarif, do you recognize this? You should, it’s yours,” Netanyahu said. “You can take back with you a message to the tyrants of Tehran — do not test Israel’s resolve!”

Tehran has denied that the drone belonged to Iran. Zarif on Sunday dismissed Netanyahu’s stunt as “a cartoonish circus… which does not even deserve the dignity of a response.”

Iranian troops, along with Hezbollah and other Iranian-backed Shiite forces, have aided Syrian President Bashar Assad in his war against rebel groups. Netanyahu has repeatedly warned that he will not accept a permanent Iranian military presence in postwar Syria, fearing that Iran and its Shiite allies would turn their attention to Israel.

Netanyahu has been projecting a business-as-usual approach on his visit to Germany amid uproar at home after police on Tuesday said was sufficient evidence to indict him for bribery, fraud and breach of trust in two cases. The Israeli leader has angrily rejected the accusations and denounced what he describes as an overzealous police investigation. He has also dismissed the accusations as a witch hunt orchestrated by a hostile media.

Zarif suggested Netanyahu might be escalating tensions with Iran simply to distract from his domestic problems.

Denouncing what he said were Israel’s “almost daily illegal incursions into Syrian airspace,” Zarif said Israel was trying “to create these cartoonish images to blame others for its own strategic blunders, or maybe to evade the domestic crisis they’re facing.”

Netanyahu told the audience that destroying the drone was a demonstration of Israel’s resolve.

“Israel will not allow Iran’s regime to put a noose of terror around our neck,” he said. “We will act if necessary, not just against Iran’s proxies that are attacking us but against Iran itself.”

Lebanese Defense Minister Yaacoub Sarraf accused Israel of being hypocritical, saying that he’d had “an Israeli drone above my head for the past 15 years” and warning about any aggression from its neighbor.

“Lebanon has no belligerent intent on anybody, but watch out, we will defend ourselves,” he said. “We also have partners, we also have friends, we also have people willing to die for their country. We are for peace, yet we will not stand for any threat and we will not accept any aggression. ”

(AP)