Iran’s state-run Fars News Agency (FNA) on Tuesday claimed the theocracy is contemplating 13 “revenge scenarios” to retaliate for the U.S. elimination of terrorist mastermind Qasem Soleimani in Iraq last week.

“The Americans should know that until now 13 revenge scenarios have been discussed in the council and even if there is consensus on the weakest scenario carrying it out can be a historic nightmare for the Americans,” threatened Supreme National Security Council Secretary Ali Shamkhani.

FNA did not go into detail about what those 13 scenarios entailed, but Supreme Leader Ayatollah Ali Khamenei reportedly swung by the National Security Council meeting to offer his thoughts on what form revenge should take.

Khamenei stipulated revenge should be “openly carried out by Iranian forces themselves” and should involve a “direct and proportional attack on American interests.”

Iran has been bubbling with threats ever since Soleimani was killed while illegally plotting attacks on Americans and Iraqis in Baghdad. Nearly every regime official of any stature has issued his own variation on the vow to take revenge.

The more recent threats, like Khamenei’s purported instructions to the National Security Council, reflect Iranian sensitivity about its reliance on illegal militia proxy forces and cowardly terrorist attacks on civilians by asserting that whatever Iran does next will be a direct attack on U.S. military forces executed by the Iranian military. Of course, American and allied defense planners would be foolish to assume the regime in Tehran will live up to either of those boasts.

CNBC reported global market jitters on Tuesday as everyone from the U.S. Department of Homeland Security (DHS) to European market analysts assumes the last thing Iran will do is send uniformed military forces to honorably challenge American troops to a fight, especially with Tehran severely weakened by U.S. President Donald Trump’s sanctions.

DHS is concerned about the possibility of infrastructure attacks and cyber espionage within the United States. Others envisioned surprise attacks on U.S. allies in the Middle East, most likely involving the proxy terrorists such as Hezbollah and the Iraqi Shiite militias that Khamenei ostentatiously forbid using. Strikes against Middle Eastern oil infrastructure and Persian Gulf shipping are strong possibilities since Iran has taken such actions unprompted in the recent past.

Carnegie Endowment senior fellow Karim Sajadpour told CNBC the Iranians must “respond in a way which is pretty forceful or else they risk losing face,” but added that “with the erraticness of Trump, they have to be very careful about how they respond.”