WASHINGTON — National security adviser Susan Rice appeared to be channeling her namesake and Republican predecessor Condoleezza on Monday [Sept. 9], when she insisted that if the United States failed to strike Syria for its apparent use of chemical weapons “more of the world’s most dangerous weapons” could wind up in “the world’s most dangerous hands.”

Iran and North Korea, Rice claimed, “will be emboldened to push harder for the world they want,” if the United States does not act. “We will not allow Iran to acquire a nuclear weapon,” Rice told an audience at the New American Foundation in Washington. “For our efforts to succeed, the leaders in Tehran must know the United States means what it says.”

Rice’s comments echo those of President Barack Obama, Secretary of State John Kerry and others in the administration who have based their public justification for striking Syria on a Chinese menu of rationales that includes impressing Iran. But the Iran argument — while understandable in domestic US political terms — is both flawed and risky, conflating a more narrowly supported goal of responding to and deterring the use of chemical weapons with the much broader-based international aim of preventing Iran from developing nuclear bombs.

By insisting that Iran will be “emboldened” to pursue nuclear weapons in the absence of military action against Syria, US officials risk making themselves look weak in upcoming nuclear negotiations if the US Congress and much of the world balk at endorsing US strikes against Syria. Setting up a Syrian straw man also detracts from the US administration’s success over the past five years in building an international coalition on Iran that includes unprecedented economic sanctions.