As Congress plays its customary ‘bad cop’ role in support of a satisfactory nuclear deal by proposing still tighter sanctions—the one factor Washington experts seem to agree has prompted Tehran’s conciliatory turn—it is unclear how the US negotiators can elicit from Mr. Zarif and his masters a sufficient Iranian compromise that will not look to all the world like a capitulation. And if the US side cannot bring to the table assurances of sanctions relief sufficient to seal an acceptable deal, its predicament may induce paralyzing caution on other policy fronts deemed important to Tehran, lest the collaborative spirit at the nuclear talks be spoiled.

All three negotiations underway, regarding Israel-Palestine, Syria, and Iran’s nuclear program, are inescapably attached to larger region-wide dynamics that will frustrate American objectives if not addressed by US foreign policy. President Obama needs a strategy.

American Interests, American Principles, American Influence—an American Strategy

Policy veterans in Washington cannot point to any prior case where economic sanctions have “kicked in” strongly enough to produce the desired result—until now. Sanctions against the regimes led by Slobodan Milosevic, Saddam Hussein and Bashar al-Assad produced scarcity and hardship for the poorest of their citizens but enriched the leadership circle, who exacted higher rents on the basic commodities they alone could smuggle in.

Kudos to the US Treasury Department for locating and constricting the key transactional nodes through which Iran’s economy connects to the world. Yet the tool of economic sanctions against Iran, while more potent than any previous instance, should be troubling to US policymakers. With the exception of the clerical regime, Iran’s 79 million people ought to be the target of American goodwill, not collective punishment for the acts of their dictators. Sustaining the US economy as the world’s strongest depends on free trade; a latter-day ‘blockade’ of any country by the United States should be a rare exception, for policy and moral reasons.

One consequence of the Iran sanctions that mirrors past cases, as Fareed Zakaria has pointed out, is that Iran’s Revolutionary Guards “profit from the sanctions because their businesses have become the only path for trade and smuggling.”

For these reasons, President Obama should strengthen his negotiating hand with Iran by collaborating with Congress to make clear, not just what further economic pain and isolation will result from Tehran’s refusal to accept a verifiable end to its nuclear weapons program, but the relief and rewards that a comprehensive nuclear concession by Iran’s leaders will produce. Every citizen of Iran should become aware that the US is offering an end to those sanctions that were created for the purpose of pressuring Iran on the nuclear issue—whether via executive order or legislation. The Congress could also indicate its readiness in principle to support the lifting of UN Security Council sanctions relating to the nuclear issue.

This step would place the onus for compromise back on the Iranian side of the negotiating table, forcing the regime to explain to its people why it would not accept a deal codifying what it has already said is its policy, namely that it does not seek to build nuclear weapons that it wants sanctions relief in order to secure an immediate upsurge in the entire country’s standard of living. Assuming Iran can say yes to comprehensive nuclear restraints for comprehensive sanctions relief, the Revolutionary Guards’ lucrative smuggling business would be over. More importantly, the terrible choice between war with Iran or a regional nuclear arms race would be averted.

Reciprocating President Rouhani’s expressed desire for improved relations, the Congress and administration should even consider fattening Iran’s ‘prize’ for an acceptable nuclear deal with a package of increased student visas, cultural and sporting exchanges and the like. Steps to empower Iranian civil society economically, counter internal censorship and propaganda, and spread goodwill between the two countries’ populations are all consistent with US security interests once the nuclear weapons threat is reliably controlled.

What President Obama should avoid, however, is encumbering the nuclear negotiation with other issues complicating US-Iran relations. “We are not seeking regime change,” Mr. Obama declared at the UN in September. This statement cleverly spoke to two audiences—the clerics in Tehran whose singular priority is remaining in power; and the president’s domestic political allies who associate ‘regime change’ with neoconservative attitudes favored in the previous administration.

A more appropriate formulation in the President’s speech would have made clear that if his Administration does not seek regime change, it carries no particular brief to maintain this regime in power either. The principle of popular sovereignty should be at the heart of US policy, and given the storied history of US meddling in Iranian politics, Iranian leaders would be hard-pressed to complain if an American president said that the Iranian people should have the ultimate say in how they are governed.

The fact is that Hassan Rouhani and the Iranian Foreign Ministry do not represent the Islamic Republic on some major issues relevant to negotiations in the Middle East. The commander of the elite Qods Force atop the Revolutionary Guards organization, Qassem Suleimani, is leading the effort in Syria to train and resupply Lebanese Hezbollah fighters in defense of the Assad regime—a vital interest to the Tehran regime, as noted. Suleimani also appears to run the “Iraq” account for Tehran, coordinating with Prime Minister Maliki in support of extralegal killings of defenseless Iranian dissidents inside Iraq by a special unit of Iraqi forces attached to the Prime Minister’s office.

The paramilitary campaigns supported by Iran’s Revolutionary Guards in Syria and Iraq are not unconnected to American interests. In Iraq, five armed attacks since mid-2009 by Iraqi military units, or by Iranian-supplied militias passing through their lines, against more than 3,000 unarmed Iranian dissidents place the United States in breach of its obligations under the Fourth Geneva Convention. A promise of protection, formally given by the US to every one of these individuals in 2004, remains an American duty today because the Iraqi government has repeatedly violated its 2009 commitment to provide protection for these people, engaging instead in lethal attacks against them in coordination with Tehran.

The US understandably wants a robust and lasting security assistance relationship with Iraq’s armed forces after so much sacrifice by American forces in Iraq. Yet it is compromised by its failure to live up to not only international humanitarian law, but Section 3 of the Arms Export Control Act prohibiting arms transfers to militaries that misuse them, and the so-called Leahy Human Rights laws prohibiting training for any military units implicated in gross human rights violations.

The latest assault, the September 1 execution of 52 defenseless Iranian exiles by Iraqi special forces using handcuffs and silencers, and the abduction of seven others who are still missing, occurred five days after Qassem Suleimani met with Prime Minister Maliki and his aides to plan the operation, according to the exiled group, the MEK. The massacre went largely unreported in the American media, the story overshadowed by the September 2 announcement in Tehran of President Rouhani’s plans to travel to the United States.

America’s policy lapses in both Syria and Iraq, the portfolio directly overseen by Qassim Suleimani on Iran’s behalf, come as well at the expense of Iran’s regional strategic rival: the Sunni Arab world and Saudi Arabia in particular. Writes veteran international correspondent Arnaud de Borchgrave, “The longer the fighting in Syria, the more the situation in Iraq deteriorates and the closer Iran’s military ‘mullahocracy’ comes to dominating the entire region.”

The Administration’s recent move restricting Egypt’s military assistance pipeline—a cornerstone of the Israel-Egypt peace treaty that has kept Israel’s southern flank quiet for 34 years—only adds to the insecurity felt by America’s longstanding Arab allies as well as Israel.

President Obama must separate these wider complications of US-Iran relations from the nuclear negotiations, but without disregarding them. Although Mr. Obama expressed the hope at the UN that a nuclear agreement with Iran can “help serve as a foundation for a broader peace,” it should be clear that Tehran’s Revolutionary Guards have every intention to continue prosecuting their campaigns, working through extremist non-state actors, to destabilize rival societies to the west.

Until the day comes when no more Iranian arms, money, explosives and training are flowing to client militias, Ambassador Indyk is going to need to point to a regional American security posture that Israelis and Palestinians can believe in should they be otherwise prepared to bring forth an historic final-status settlement. If at the same time Egypt’s military is casting about for alternative strategic partnerships, Mr. Indyk’s task will be that much more daunting.

The US has every right, and every interest, in pursuing its own interests throughout the Middle East. If success in effecting a transition in Syria to a more acceptable successor government is taken as a setback in Tehran, that should not deter Washington. Nor should the US hesitate any longer to impose a principled, legally correct line with Iraqi Prime Minister Maliki in order that US-Iraq military relations will not be further tainted by dishonor or moral compromise. Should the Obama team see fit to reaffirm its commitment to the security of Saudi Arabia and the Gulf Arab states, and to Egypt’s military, this rebuilding of confidence with the Sunni Arab world should neither surprise Iran nor perturb the nuclear negotiations. ‘Peace through strength’ has always entailed much more than combat power alone.