European diplomats are warning that enhanced U.S. financial sanctions against Iran run the risk of forcing the rest of the world to create alternative banking systems that could undermine the long-time dominance of the U.S. dollar, Washington Examiner reported.

The issue has come up as the Trump administration considers aggressive sanctions aimed at expelling Iran from the international banking system. As the deadline for sanctioning Iran’s oil industry approaches, the spotlight has shifted to the Society for Worldwide Interbank Financial Telecommunication, an entity led by representatives of major banks from the world’s 10 largest economies that helps banks around the world communicate with each other on transactions.

The United States doesn’t control the global group, but Trump could threaten to ban those board members from working in the U.S. financial system if they help Iranian banks defy U.S. sanctions.

That move is potent because SWIFT “facilitat[es] global and local financial flows” by providing the financial industry a secure way of communicating. By pressuring SWIFT to expel Iran from the network, the U.S. could suffocate the regime’s economy.

But that possibility is also raising questions about how the world might react. One Western diplomat said the move could be enough to accelerate talks about the need for alternative systems that don't rely on the U.S. dollar and U.S. policy, a move that could eventually end up hurting the U.S. dollar.

“At the moment, sanctions are effective because of U.S. financial dominance as the global reserve currency — forcing SWIFT out of Iran could incentivize China or Russia to establish their own SWIFT system, which is not in any of our interests,” the diplomat told the Washington Examiner.