It's the economy, stupid.

Iranians courageously taking to streets against their religious tyrants have expressed various motivations, including the desire for freedom and their rage at corruption. But their fury burns hottest about their government's economic mismanagement. Over the last 10 years, real incomes have plummeted, food consumption has declined, and inflation has remained high.

President Trump, rightly, has said America will offer "great support" to these suffering citizens.

But what should that support entail? The president should work to divert sanctions relief-related economic benefits into the hands of the Iranian people and away from those who rule them.

Many business deals that agreed to following former President Barack Obama's 2015 nuclear agreement have flowed into the hands of regime hardliners.

Siemens, for example, is heavily involved in multibillion dollar construction projects with an Iranian company called MAPNA. This company, Siemens says, "improves quality of life in Iran with reliable, efficient, and safe transportation." What Siemens doesn't say is that MAPNA has been linked to research for weapons of mass destruction.

Deals like this, however, are not the first choice of European multinational companies. Concerned about future sanctions, their advisers and risk analysts recommend that businesses avoid Iranian organizations linked to hardliners. They might complain in the beginning, but over time, they would appreciate the stability of a reformed arrangement.

Hardliners operate vast networks of business fronts across the Iranian economy, especially in construction, energy, and telecommunications, so they have an effective veto of many a business deal. A significant portion of Iran's GDP is held in charitable trusts and holding companies under the direct control of Ayatollah Ali Khamenei. While officials claim these organizations exist to serve the poorest in Iran, their real purpose is to entrench economic power in the hands of the regime's true believers.

The Obama administration has much to be ashamed of here. Its appeasement of Tehran and its proxies continues to be documented. It should have worked with America's European allies to ensure that sanctions relief flowed more directly to Iran's populace.

The Trump administration can right that wrong. President Trump's grand opportunity is to use access to the U.S. economy as a lever with which to pressure European governments to support his reform efforts. If forced to choose between access to American or Iranian markets, European multinationals will choose the former.

Trump should pick up the phone, call the heads of state in France, Germany, and the United Kingdom, and tell them that, in return for his continued support for the nuclear agreement, he will expect them to crack down on Iran's ballistic missile activities and divert economic benefits to the Iranian people and away from their persecutors.

He should establish a joint U.S.-British-French-German committee to audit Western business requests to deal with Iranian counterparts. The auditors could assess whether the Iranian businesses were independent, uncorrupted, and privately organized and whether the proposed deal would help ordinary Iranians rather than the regime. Companies that fail the audit would be blacklisted. If Western companies could not find a decent counterpart, the audit-business committee could help establish a new independent corporate partner in Iran. Iran says it encourages its citizens to grasp new opportunities and build a better economy, so put it to the test.

This proposal will allow European governments to protect their economic interests while helping a suffering population. European governments would prefer to allow their businesses to keep dealing with the hardliner fronts in order to please the regime, but Trump's Twitter feed can remind them of their oft-stated commitment to human rights.

This arrangement would put Iranian hardliners in a difficult position. They claim the U.S. is directly responsible for the economic suffering that brought so many to the streets. If Trump replies, "Here is our proposal to put billions of dollars into the hands of Iran's people," what can Iran's leaders say in response? They can try to paint successfully audited companies as traitors, but Iranians will see through those lies.

This proposal offers the art of a better Iran deal. It will allow Trump to secure America better, help sustain a nuclear deal that our allies care much about, and alleviate Iranian suffering.