One potential answer is that Iran’s regime is not genocidally anti-Semitic, only genocidally anti-Zionist. It will spare its own Jews, provided they eschew Zionism, while killing the Jews of Israel because they will not.

But even toward Israel, Iran’s behavior, while hostile and violent, has been nowhere near genocidal. To be sure, Iran supports both Hezbollah and Hamas, organizations that commit terrorism against the Jewish state (and in the case of Hezbollah’s despicable attack on a Jewish community center in Buenos Aires in 1994, terrorism against Jews outside Israel too). Supporting these groups furthers Iran’s regional influence, since it allows Tehran to pose as the champion of a Palestinian cause that most Arabs support. It also strengthens Iranian deterrence, since Hezbollah and Hamas, which are situated on Israel’s borders, could retaliate if Israel attacked Iran.

But while Iran supports Hezbollah and Hamas, it has not done everything in its power to help them kill Israelis. Not even close. To the contrary, the regime’s apparent fear of Israeli retaliation generally has led it to exhibit the very restraint that Huckabee, Cruz, and Netanyahu insist it would not show once it has the bomb.

Consider a few examples. In his book Unthinkable, the Brookings Institution’s Kenneth Pollack notes that although Iran likely has biological weapons, it has not given them to Hezbollah. In 1982, when Lebanese Shia leaders asked Iran to send troops to repel Israel’s invasion of Lebanon, the then-supreme leader, Ayatollah Ruhollah Khomeini, refused. In 1996, Iran pressured Hezbollah to agree to a ceasefire with Israel. And as Trita Parsi notes in his indispensable book on Iranian-Israeli relations, Treacherous Alliance, Israel’s then-defense minister, Yitzhak Mordechai, even praised Tehran for its efforts to return Israeli soldiers that Hezbollah had captured. In 2001, according to Parsi, leaders of Hamas and Islamic Jihad vented frustration that Iran was not offering them greater assistance during the Second Intifada. And in 2003, after the U.S. invasion of Iraq, Iran offered the United States a grand bargain that included an offer to cut ties to Hamas and Islamic Jihad and pressure Hezbollah to shut down its military wing if the United States ended sanctions and restored diplomatic ties.

Indeed, despite Netanyahu’s rhetoric, Israeli leaders have not generally acted as if they consider the Islamic Republic to be genocidal. In the early 1980s, the Iranian regime spewed even more ferocious anti-Israel propaganda than it does now. At one point it sponsored a pan-Islamic contest in which children were encouraged to draw pictures and write essays on the topic, “Israel Must Be Erased from the Earth.” Nonetheless, Israeli leaders—seeing Saddam Hussein as the greater threat—sold Iran weapons during its war against Iraq. They urged the United States to do so too, and in the process played a key role in the Iran-Contra affair. “Throughout the 1980s, no one in Israel said anything about an Iranian threat,” notes Tel Aviv University Iran expert David Menashri. “The word wasn’t even uttered.”

As Parsi argues convincingly, Israeli claims about Iran’s genocidal intent only began more than a decade after the Islamic Republic was established. They occurred not in response to any change in Tehran’s rhetoric or behavior, but in response to a fundamental shift in the strategic landscape. In the 1980s, Israeli anxieties had centered on Saddam’s Iraq, which was geographically closer to Israel and with Soviet help had built the world’s fourth-largest army. But in the early 1990s, Saddam’s power collapsed. Iraq lost its major patron when the U.S.S.R. fell, was humiliated in the Gulf War, and became the subject of global sanctions. It was only then that Israeli leaders began describing Iran as the primary danger—a perception that grew after the United States toppled Saddam in 2003, creating a political vacuum that pro-Iranian forces filled. In the words of retired Israeli Brigadier General Shlomo Brom, “Nothing special happened with Iran, but because Iraq was removed, Iran started to play a greater role in the threat perception of Israel.”