They're weighing whether to order Hezbollah to launch rockets at Israel or target U.S. warships in the Mediterranean. Or they could send shadowy groups for suicide-bomb attacks against Israelis and Americans. Or, as one blogger has called for, they could try kidnapping families of American military officers in far-flung corners of the globe.
Or Iran may do nothing.
One thing, however, is clear: The debate over whether Congress approves the Obama administration's plan to strike Syria for its use of chemical weapons is being watched nowhere more closely than in Iran, where the notoriously opaque political leaders are wrestling over whether — and how — to retaliate.
However, most observers in Washington are still trying to make sense of Mr. Rouhani's relationship with Ayatollah Khamenei and Gen. Suleimani.
"I think Syria is a real window into the soul of the Iranian regime and a real test of whether or not Rouhani has not only different intentions than his predecessor but whether he has the capacity to implement a significant shift in Iranian foreign and national security policy," says Mark Dubowitz, executive director of the Foundation for the Defense of Democracies.
"The question is really how does Tehran's revolutionary elite see Syria and does Rouhani's perception of Syria depart in any way from the supreme leader" and the military, Mr. Dubowitz said. "If Rouhani were a moderate leader, then is he using his influence to question the supreme leader's support for the Assad regime in Syria?"
Meanwhile, the extent and details of the relationship between Iran and Syria remains mysterious, although the two nations have been allies to some extent since the 1980s, when Syria was the only major Arab state to side with Iran in its war with Saddam Hussein's Iraq.
For instance, it is difficult to gauge whether Tehran was directly involved in Mr. Assad's recent decision to use chemical weapons against rebel-held civilian areas. Iran was itself the victim of the most-widespread and significant use of chemical weapons since their development a century ago — by Saddam during their nations' eight-year war.
"My sense is that the Iranian leadership is very ticked off at Assad," said Mr. Parsi, who added that some in Tehran likely see the Syrian president as acting recklessly and thus "undermining their objective of making sure that [he] survives."
Alternatively, Mr. Dubowitz contends that "Assad would not have used chemical weapons without the approval and the knowledge" of key players in Tehran, if only Gen. Suleimani, since he is believed to be in control of Iranian forces on the ground inside Syria.
"I don't believe there's a strategic and operational gap between the Iranian regime and Assad," Mr. Dubowitz said. "So it may turn out to be a massive Iranian miscalculation to have permitted Assad to use chemical weapons. I think the reason they did though is because they truly believed President Obama was bluffing. I don't think they thought he was serious about intervening in Syria."