Various approaches can be used to counter threats posed by a rogue state. But is diplomacy alone adequate to deal with the Iranian regime? US President Joe Biden still believes that diplomacy is the best policy to counter and deal with Iran. He said on July 14: “I continue to believe that diplomacy is the best way to achieve this outcome. We will continue to work with Israel to counter other threats from Iran throughout the region, including support for terrorism, a ballistic missile program that continues, and the proliferation of weapons to terrorist and proxies like Hezbollah.” The Biden administration has adopted this soft policy toward the theocratic establishment of Iran since it assumed office in January 2021. Appeasement, conciliation and concessions have appeared to be part of this diplomatic route from the outset. The Biden administration first declared to the Iranian government that it not only wanted to remove nuclear-related sanctions, but also that it was willing to lift some of the non-nuclear-related curbs if the nuclear deal was revived between Tehran and the P5+1 — China, France, Russia, the UK and US, plus Germany. Later, this was followed by significant concessions toward one of Iran’s main proxies, the Houthis. Despite evidence that the Iranian regime was delivering sophisticated weapons to the militia, the Biden administration suspended some of the anti-terrorism sanctions on the Houthis and, soon after, revoked the designation of the militia as a terrorist group. What was the outcome? This move, of course, was a significant victory for the Iranian leaders and the Houthis, but it came at a huge cost for countries such as Saudi Arabia, which is the main target of the Houthis’ rocket and drone attacks. In fact, only a few days after removing the Houthis from the list of foreign terrorist organizations, the State Department had to call on the militia to “immediately cease attacks impacting civilian areas inside Saudi Arabia and to halt any new military offensives inside Yemen.” By removing Iran’s proxy from the terrorist list and cutting off US support to confront the militia group, the Biden administration emboldened and empowered the Houthis and its paymaster, the Iranian regime, which in turn, ratcheted up the smuggling and delivery of weapons to the militia. If Biden insists on employing diplomacy with the Iranian regime, he must at least follow the approach advocated by former US leader Theodore Roosevelt: “Speak softly and carry a big stick.” Dr. Majid Rafizadeh On Jan. 17, 2022, the Houthis launched a military attack on the UAE, blowing up three oil tanker trucks in Abu Dhabi and killing three people. In February 2021 alone, the Houthis fired more than 40 drones and missiles at Saudi Arabia. Even Western officials had to acknowledge the escalation. As a senior US defense official told NBC News on condition of anonymity: “We’re certainly aware of a troubling increase in Houthi cross-border attacks from a variety of systems, including cruise missiles, ballistic missiles and UAVs (unmanned aerial vehicles).” But the Biden administration"s diplomatic overtures with the Iranian regime did not end there. In June 2021, the White House lifted sanctions on three former Iranian officials and several energy companies. Then, it announced that it was also considering lifting sanctions against the Supreme Leader Ali Khamenei. In addition, other appeasement efforts have included turning a blind eye to the regime’s destructive behavior in the region and beyond, which includes smuggling weapons to the Houthis, shipping oil and weapons to Venezuela, harassing the US Navy and targeting US bases in Iraq. Iran’s shipment of weapons to Venezuela have included advanced arms such as “171 guided anti-tank missiles, eight surface-to-air missiles, land attack cruise missile components, anti-ship cruise missile components, thermal weapon optics and other components for missiles and unmanned aerial vehicles (drones).” Other violations by the Iranian regime have also been disregarded. The ruling mullahs of Iran violate US sanctions and UN security resolutions without facing the consequences. For example, shipments of weapons to the Houthis in Yemen are a violation of UN Security Council Resolution 2140, which states: “Obligation to freeze all funds, other financial assets and economic resources that are owned or controlled, directly or indirectly, by the individuals or entities designated by the committee, or by individuals or entities acting on their behalf or at their direction, or by entities owned or controlled by them; no funds, financial assets or economic resources to be made available to or for the benefit of such individuals or entities.” In conclusion, history has repeatedly shown that pursuing diplomacy alone with the Iranian regime will ultimately fail. The Biden administration’s diplomatic strategy has led only to a more aggressive regime in Tehran, which is now extremely close to acquiring nuclear weapons. If Biden insists on employing diplomacy with the Iranian regime, he must at least follow the approach advocated by former US leader Theodore Roosevelt: “Speak softly and carry a big stick.” • Dr. Majid Rafizadeh is a Harvard-educated Iranian-American political scientist. Twitter: @Dr_Rafizadeh