As Iran’s nuclear weapons program pushes forward, the European Union is dragging its feet on implementing sanctions that would help cripple the Iranian regime’s progress.

This week, eight U.S. Senators sent a letter to Lady Catherine Ashton, the European Union’s high representative for foreign affairs and security policy, urging the EU to impose an immediate oil embargo as well as sanctions against the Iranian Central Bank.

Despite Iran’s increasing belligerence—test-firing new missiles, threatening to shut down the Strait of Hormuz, and announcing the production of its first nuclear-fuel rod—Greece, Italy, and Spain are reluctant to agree to tough sanctions. Iranian oil makes up 35 percent of Greece’s oil imports, heightening fears that a shock to its oil supply would deepen the country’s economic woes. Italy agrees to the oil sanctions in theory but wants its existing contracts excluded.

The United Kingdom, which imposed its toughest sanctions to date last November, is urging EU member states to impose a ban on all Iranian financial institutions. However, by objecting to mechanisms that would reduce Iran’s capabilities, some of the same countries responsible for Europe’s debt crisis are undermining the security of their own citizens as well.

On January 23, European foreign ministers will meet to decide on a course of action against Iran. It is important that America’s allies in Europe send a clear signal that Iran’s drive to become a nuclear-armed power is unacceptable.