What do Venezuela, Nicaragua, Cuba and Ecuador have in common as we start 2012? The controversial visit of Iran’s Mahmoud Ahmadinejad. Apparently, the Iranian leader, facing additional international economic sanctions, increasing internal political pressure and a deteriorating economy, decided it was a good strategy to highlight the support of these four leftist regimes in our region.

In fact, Ahmadinejad’s failure to comply with the U.N.’s nuclear nonproliferation agreements has prompted the United States and the European Union to announce new economic sanctions, including the possibility of an oil embargo by the end of January.

As a reaction, the Iranian government is causing dangerous global tensions with its military maneuvers around the Strait of Hormuz threatening to close the important transit route of oil to the world.

The United States has plenty of reasons to be concerned about Iran’s growing influence in Latin America and the Caribbean. After all, the Iranian government and its four leftist allies share a visceral hate for all that the United States stands for. All five governments are embarked, although at different stages, on a course to undermine our values of democracy and self determination. It is time for the Obama administration to show its willingness to face the challenge in no uncertain terms.

Mario J. Sacasa, former consul general of Nicaragua, Miami