Iranian President Hassan Rouhani’s visit to the United States culminated on Friday in the first conversation between the Iranian and American presidents in over three decades. With a new round of negotiations between United Nations Security Council members and Iran set to take place later this month, an important national security concern of the United States is at stake.

Iran is the world’s foremost sponsor of terrorism, it has acted against U.S. interests across the globe for decades, and a nuclear weapon would only effectively insulate the theocratic regime from both internal and external opposition. But it is unclear that President Obama’s effort will bring Iran around.

In a recent interview, Israeli Prime Minister Benjamin Netanyahu warned that if the current regime in Tehran had nuclear weapons, it would pose a threat to the Iranian people, Israel, neighboring Arab states, Europe, and the U.S. alike. Tehran continues to support a Syrian regime that has used chemical weapons against its own people. It is not a regime whose threats of destroying America and our allies should be taken lightly.

According to Heritage’s Kim Holmes, the U.S. is sending mixed messages to Iran and others who do not share our interests. There is a debate to be had over what national interests are “core,” as President Obama defined them at the U.N. last week. Dissuading the Islamic Republic of Iran from going nuclear is clearly one of them. But as Tehran continues to march toward obtaining them, the Administration has yet to act in a way that will dissuade them.

“Power is a tricky business,” says Holmes. “Use it and fail, and it is gone. Don’t use it all, and it ceases to exist. We indeed need a middle way, but not between some theoretical opposites of idealism versus realism.… Rather, the debate should be about which core interests require military force to defend.”

Leo Nayfeld is currently a member of the Young Leaders Program at The Heritage Foundation. For more information on interning at Heritage, please click here.