By Tom Ridge

Last week, Iran's Supreme Leader Ali Khamenei accused the United States of failing to honor pledges in the Joint Comprehensive Plan of Action (JCPOA). Citing "the futility of negotiations with the Americans," he distanced himself from the nuclear deal he once supported.

Coming just weeks after the one-year anniversary of the agreement, his charge is just another in an escalating war of words from Tehran that remind the world that the "era of good feelings" promised by U.S. negotiators never came to pass. Nor have Iran's nuclear ambitions.

Tehran's change in tune should come as no surprise. Intelligence reports have long warned that the regime continued its attempts to obtain illicit nuclear material right up to the brink of implementation of the deal. And while the accord did institute constraints on Iran's uranium enrichment program and its capacity for producing weapons-grade plutonium, the vast majority of Iran's nuclear infrastructure remains in place.

Iran's problematic behavior was recently underscored by Robert Joseph, former U.S. special envoy for nuclear nonproliferation, during a recent panel discussion in Paris. He cautioned that the JCPOA had only compelled Iran to dismantle some of its enrichment centrifuges while leaving them safely inside the country, ready to be re-engaged at the first opportunity.

The current state of the deal stands in stark contrast to the world community's prior successes with other nuclear threshold states. Libyans, for instance, demonstrated a genuine and tangible commitment to abandoning the pursuit of nuclear weapons insofar as they fully opened up their country to impartial international inspections. Iran has come nowhere close to this.

The lack of transparent monitoring has been a major point of unease among critics and initial supporters of the nuclear agreement alike. The deal only establishes international surveillance of declared nuclear enrichment sites, failing to address the likelihood that illicit nuclear development is taking place in secured locations, undetected by foreign intelligence agencies.

This would not be the first time that Iran successfully slipped its nuclear efforts under the international radar.

In 2002, it was not Western investigation but the Iranian resistance group Mujahedin-e Khalq (MEK) that revealed the essential details of the Iranian nuclear program. If not for this intelligence breakthrough, the regime would likely already be armed with nuclear weapons.

Nuclear limitations aside, it's hard to imagine that the hoped-for shift in Tehran's foreign policy will materialize. The strategic contours are set by the supreme leader himself, whose support for Syrian dictator Bashar Assad is unwavering. Various credible reports indicate that thousands of Islamic Revolutionary Guard Corps members are now operating in Syria.

Western policymakers should have recognized that the theocracy is inherently incapable of reform. If history is any guide, Tehran will exploit every weakness in the nuclear agreement as part of its relentless effort to deceive its enemies. And, it will use the current environment of Western complacency to intensify regional adventurism and support for extremist thought.

In a similar stroke of naiveté, proponents of the deal mistakenly assumed that Tehran would clean up its domestic behavior. But political opponents and activists continue to be arrested, tortured, and executed in increasing numbers. During the administration of supposedly "moderate" Hassan Rouhani, the regime has executed at least 2,600 prisoners, including many dissidents - an unprecedented figure by any standard.

Overall, the deal has led to no progress. In return for modest, reversible concessions on the nuclear issue alone, the blood-drenched ayatollahs received sanctions relief from the United States and Europe to the tune of tens of billions of dollars, which has served, above all else, to further finance the Iranian regime's illicit, inhumane, and destabilizing activities. If the regime decides to abandon the deal, it will emerge stronger than ever before, laughing in the face of the West's foolish compliance.

Let Khamenei's bellicose rhetoric stand as a warning and a call to action. Every interested American should urge the next president to chart a different, sensible course for American policy toward the fundamentalist regime in Iran. This course should, at last, reflect American values by identifying itself with the Iranian people and their cry for democracy and freedom.

Tom Ridge was the nation's first secretary of homeland security and served two terms as governor of Pennsylvania. @RidgeGlobal