A former American diplomat told CNN on Wednesday that Iranian involvement in a suspected plot that aimed to assassinate the Saudi ambassador to the United States “makes no sense.”

According to Hillary Mann Leverett, “there is no benefit, there is no payoff from them pursuing this kind of hit against Al-Jubeir,” the Saudi diplomat who was the target of a conspiracy that allegedly involved members of Iran’s Revolutionary Guard. “It runs contrary to their entire national-security strategy,” she added. “We have a plot but no rationale.”

Leverett served on President George W. Bush’s National Security Council and negotiated with the Iranians on behalf of the United States between 2001 and 2003 when the country invaded Afghanistan. She is now a senior research fellow at Yale University’s Jackson Institute for Global Affairs.

On CNN, Leverett cautioned against assuming that Iran would carry out an assassination attempt even if it didn’t rationally serve their interests. “This would be such a significant departure for the Iranian government to be involved in something like this,” she said.

Iran and Saudi Arabia have been at odds for several decades in the Middle East. Both nations aspire to regional hegemony but for very different purposes. Whereas Saudi Arabia seeks a favorable balance of power to ensure a stable oil trade, Iran officially aims to “export” its Islamic revolution. It funds militant Islamist movements like Hezbollah to that end.

Iranian-Saudi tension was exacerbated by the “Arab Spring” earlier this year when Bahrain’s Shia majority took to the streets to demand political representation. Iran, a Shia country, supported the uprising but Saudi allegations notwithstanding, there was no evidence that it backed it with anything but rhetoric.

Saudi Arabia nevertheless intervened with other Sunni monarchies to quell the protests in the island nation. Some 2,000 Saudi and emirate forces were deployed to suppress the demonstrations and deter Iranian encroachment on the Arabian Peninsula.

The suspected Iranian assassination plot of the Saudi ambassador to the United States may have been designed as retaliation for March’s military action but to stage such a countermeasure on American soil and risk American retaliation seems wholly disproportionate to the stakes involved.

Historically, Leverett pointed out, Iran hasn’t taken such chances. “Between 1980 and 1988, during the Iran-Iraq war, the Iranians saw the Saudis as completely financing and paying for Iraq’s war on Iran that cost 300,000 Iranians their lives. During that entire time, they didn’t hurt a single Saudi citizen anywhere in the world.”

Leverett stressed that the irrationality of official Iranian involvement in the plot doesn’t necessarily suggest a fabrication of evidence on the part of the United States although she pointed out there is precedent that for that. During her time in the Bush Administration, Iraq was alleged to have purchased uranium fuel in Niger which proved to be false.