The nuclear agreement signed by Iran and the six major powers in July has emboldened the Iranian leadership to carry on as usual with its aggressive foreign policy in the Middle East.

Under the terms of the accord, Iran agreed to curb its nuclear program for 10 to 15 years in exchange for sanctions relief to the tune of about $100 billion. Critics of the deal, notably Israeli Prime Minister Benjamin Netanyahu, warned that the funds freed up by the agreement would encourage Iran to pursue policies detrimental to Israel and Sunni states in the region.

“Unleashed and unmuzzled, Iran will go on the prowl, devouring more prey,” Netanyahu said in a speech to the United Nations General Assembly on September 30. In a withering aside, he wondered why some world leaders are naive enough to believe that Iran will change from a “rapacious tiger into a kitten.”

U.S. President Barack Obama, in his address to the UN a few days earlier, hailed the agreement as a triumph of diplomacy, asserting it would keep Iran’s nuclear ambitions in check. Nonetheless, he urged Tehran to “work cooperatively with countries beyond its borders” rather than “deploy violent proxies to advance its interests.”

Iran’s overarching objective in the Middle East is no mystery. Iran wants to extend its influence through alliances with Shiite governments in Syria and Iraq and with Lebanese Shiite organizations like Hezbollah.

As well, Iran seeks to eradicate Islamic State, a Sunni jihadist group which threatens Iraq and Syria and may yet threaten Iran itself.

Iran and the United States, which have not had diplomatic relations since Iranian mobs stormed the U.S. embassy in Tehran in 1979, are at odds over key Mideast issues. But both share an interest in defeating Islamic State, its sister organization, Al Qaeda, and the Taliban in Afghanistan.

Hassan Rouhani, the president of Iran, struck a fairly moderate chord when he expressed interest in using the agreement to broaden cooperation with the West. As he told the UN General Assembly last month, “From our point of view, (it) is not the final objective but a development which can and should be the basis of further achievements to come.”

He added, “I say to all nations and governments. We will not forget the past, but we do not wish to live in the past. We will not forget war and sanctions, but to look to peace and development.”

Iranian Foreign Minister Mohammad Javad Zarif, Rouhani’s protege and Iran’s chief negotiator at the nuclear talks, delivered a similar message following a meeting with U.S. Secretary of State John Kerry at the UN in September. “We need to achieve peace and a way forward in the region,” he said in a reference to the Middle East. “I think there are opportunities … to make some progress.”

Anyone who thinks that Rouhani and Zarif have laid the groundwork for a new Iranian policy in the region is engaging in self-deception, as a truculent speech by Iran’s supreme leader, Ayatollah Ali Khamenei, indicated.

Distancing himself from Rouhani, he warned on October 7 that further negotiations with the United States, Iran’s nemesis, are “forbidden.” Claiming that Washington’s intention is to subvert Iran, Khamenei claimed that the Obama administration’s goal is “to manipulate people’s revolutionary and religious thoughts.”

Judging by events on the ground, Iran remains under the firm sway of Khamenei rather than reformers like Rouhani and Zarif.

Since the nuclear accord was signed in Vienna on July 14, Iran has stepped up support for Hezbollah and Hamas, which have fought four wars with Israel in the past nine years.

Reports suggest that Iran is building a military infrastructure on the Syrian side of the Golan Heights, has supplied Hezbollah with funds to purchase advanced weaponry and has funnelled substantial amounts of cash to Hamas’ military wing in the Gaza Strip.

Iran, too, is backing Houthi fighters in Yemen battling pro-American Saudi Arabian forces.

More importantly, Iran has poured more men and materiel into Syria in a bid to prop up the Baathist regime of President Bashar al-Assad, which is locked in battle with an assortment of rebels. Iran is assisting Syria in conjunction with Russia, which has bombed rebel bases from the air and the Caspian Sea.

Meanwhile, top Iranian officials from Ayatollah Ali Khamenei on down remain implacably hostile to Israel and committed to its destruction.

In his recent UN speech, Rouhani predictably denounced Israel after having wished Jews a happy new year. Khamenei adopted a much harsher tone, predicting that Israel will disappear within 25 years.

Khamenei’s rejectionist comment was echoed by three Iranian figures at the heart of the regime.

Seyed Mahmoud Nabavi, Khamenei’s aide, declared, “We haven’t recognized the Zionist regime since the beginning of the Islamic revolution and such a policy will continue.”

Hussein Sheikholeslam, a foreign affairs advisor to the Speaker of the Iranian parliament, called for Israel’s annihilation, saying that thawing relations with Western nations would not impel Iran to alter its attitude toward Israel.

Mohsen Kazzemeini, a senior commander of the Islamic Revolutionary Guards Corps, vowed that Iran will upgrade its military capabilities in the quest to destroy Israel.

Given Iran’s truculence, a recent comment by U.S. presidential candidate Hillary Clinton should be seriously considered.

Clinton, the former U.S. secretary of state, endorsed the nuclear agreement but said it could only work if Iran is contained. Describing the Iranian government as “ruthless” and “brutal,” she recommended that Iran be confronted “across the board” so that it does not exploit sanctions relief to advance its hegemonic agenda in the Middle East.

Clinton’s prescription for containing Iran is hardly new. The Obama administration has resorted to containment, as have previous U.S. presidents. It may prove useful again in the future.