Apparently “Death to America” should be taken seriously but not literally. At least that’s the implication of the quote that Iran’s supreme leader gave to state media on Tuesday: “There won’t be any war,” said Ayatollah Ali Khamenei. “We don’t seek a war.”


In light of recent events, this seems a bit weird. Last week, the U.S. announced the early deployment of an aircraft carrier and bomber task force to the Persian Gulf to deter what Acting Defense Secretary Pat Shanahan called a “credible threat by Iranian forces.” Over the weekend, the United Arab Emirates reported that four vessels in its territorial waters, including two Saudi tankers, were attacked by sabotage. So far, the Emiratis have not said the culprit was Iran. On Tuesday, Yemeni Houthi forces (who are aligned with Iran) launched a drone attack on two Saudi oil facilities.


So is the 79-year-old Khamenei finally succumbing to senility? Perhaps. But if these attacks are in fact connected to Iran’s Islamic Revolutionary Guard Corps, then it’s worth noting what is missing so far from the target list: Americans. Indeed, the deputy commander of the mission against the Islamic State said Tuesday that he had seen “no increased threat” from Iran against U.S. and coalition troops in Syria and Iraq. (The spokesman for U.S. Central Command later issued a statement saying U.S. forces are on “a high level of alert.)


If the deputy commander is right, it makes sense. Iran may be sinister, but it is not stupid. Khamenei knows that Iran will lose a military confrontation with the U.S. - as it did in 1988, when the U.S. launched an air and sea assault against Iran’s navy. The result of that battle was that the Mullahs lost their navy.


The question for Khamenei now is which Donald Trump to believe. As usual, that’s hard to know. On the one hand, the U.S. president has made it clear that he wants the U.S. military out of Syria. He has derided America’s involvement in both Iraq and Afghanistan. And he has limited his actions against Iran to diplomatic and economic war.


On the other hand, unlike his predecessors, Trump has made it clear that his policy toward Iran will not be constrained by Europe or the United Nations. He is neither ruling in nor ruling out a military option. On Tuesday, he dismissed as “fake news” reports of a plan to send 120,000 troops to a war in Iran - then added that if he was going to attack Iran, he would send “a hell of a lot more troops than that.”


While the U.S. has been clear that it will respond with force to an Iranian attack on U.S. forces or facilities, it has been ambiguous about what it would do if Iran escalates attacks against American allies. Shanahan, for example, tweeted only that the U.S. “will hold the Iranian regime accountable” for any such attacks. Given Iran’s bellicose mood, this ambiguity could be seen as an invitation.


This presents an opportunity for Congress. There’s no need for a war resolution against Iran, and Trump would be a fool to launch an invasion. For one, Americans would not support it, and for another, the Iranian people should be the authors of their own liberation. Also, the U.S. has military options short of a full-scale invasion to respond to an attack from Iran or its proxies.


But there is ample evidence that Iran responds to pressure and threats. So a non-binding congressional resolution warning Khamenei not to escalate against U.S. forces or allies in the region might serve as a useful deterrent. Signaling America’s seriousness of purpose would go a long way toward persuading Khamenei’s henchmen that they, too, should want to avoid a war with the U.S.


Eli Lake is a Bloomberg Opinion columnist covering national security and foreign policy.