In spite of what the cynics claim, the Iran policy of the US and Gulf Arab states is well-informed and is gradually bringing about effective results.

Those who oppose the US and Gulf states’ policy toward Tehran continue to advocate for pursuing appeasement policies with the Iranian regime, despite the concrete evidence that such policies have emboldened and empowered Tehran in ratcheting up its hostile activities in the region.

A detailed comparison of the regime’s military expansionism before and after the nuclear deal ought to teach a significant lesson to those who insist on carrying out rapprochement with the ruling mullahs.

What marked the new era of total appeasement toward the Iranian regime was the Joint Comprehensive Plan of Action (JCPOA), commonly known as the Iran nuclear deal, which was reached between President Hassan Rouhani’s administration and six world powers (the P5+1, namely France, Russia, the UK, China and the US, plus Germany).

The advocates of appeasing Iran had a chance to pursue their policy against Tehran when the four rounds of UN Security Council sanctions were lifted. The result was Tehran increasing its militaristic and political influence in several countries in the region, particularly Syria, Iraq and Yemen.

Financial, advisory and military support to Shiite militia groups such as Hezbollah and the Houthis also increased to an unprecedented level. Tehran also escalated its efforts to harass other countries in the Gulf.

Offering Iran the carrot without the stick has proved to be totally unproductive. That is why the Gulf Cooperation Council (GCC) and the US have argued that pressure ought to be imposed on the theocratic establishment of Iran in order to elicit constructive changes in its behavior. Any astute observer of Iran’s politics would witness that solely appeasing the Iranian regime not only kept the underlying problem intact, but also intensified Iran’s aggressive policies in the region.

Intriguingly, since the Trump administration and the Gulf states increased the pressure on Iran, Tehran has totally halted its harassment of foreign navy ships, including US and British naval vessels, in the Gulf. During the Obama administration and after the nuclear deal, Tehran frequently and dangerously harassed foreign navy ships in the Gulf, and famously captured and detained 10 US sailors in 2016.

For an Iran policy to be effective, it ought to have three concentric circles of pressure: Diplomatic, financial, and domestic. The US and Gulf states are incorporating these three dimensions in their policy toward Iran.

Diplomatically speaking, instead of condoning Iran’s destructive behavior, the Gulf states and the US have been vocal on the global stage with respect to Tehran’s aggressive and expansionist policies in the region. President Donald Trump last week criticized Iran at the UN General Assembly, stating: “Iran’s leaders sow chaos, death and destruction.” He added: “They do not respect their neighbors or borders or the sovereign rights of nations. Instead, Iran’s leaders plunder the nation’s resources to enrich themselves and spread mayhem across the Middle East and far beyond.”

From a financial perspective, the reimposition of sanctions — as well as the concerted attempts to cut off the flow of funds to the regime that are directed toward sponsoring terror groups — have decreased Tehran’s revenues and discouraged many Western firms from signing business deals with the Iranian leaders.

Ahead of the reimposition of secondary sanctions by the US in November, Iran’s oil exports declined by about 1 million barrels per day (bpd) between April and September . The Institute of International Finance pointed out that: “Iran may continue to be committed to the 2015 nuclear deal providing the EU and others do the same. However, failure to renegotiate the deal with the US would likely bring about even deeper damage to Iran’s economy.”

Last week, the price of gold went up significantly in Iran, while Tehran’s currency, the rial, reached a historic low of 150,000 to the dollar. Saudi Arabian Foreign Minister Adel Al-Jubeir recently pointed out that the Islamic Republic was unlikely to voluntarily alter its behavior. “Unless the pressure internally is extremely intense, I don’t believe they will open up, I think they are too ideological for that,” he said.

Internally, Iran’s domestic pressures and protests against the clerical rule continue, while the US and Gulf states have expressed their support for the Iranian people.

The US and Gulf states’ policies toward Iran are working. Solely offering the Iranian regime carrots is perilous and counter-productive.

• Dr. Majid Rafizadeh is a Harvard-educated Iranian-American political scientist. He is a leading expert on Iran and US foreign policy, a businessman and president of the International American Council. Twitter: @Dr_Rafizadeh