The United States was quick to blame Iran for last week’s attack on two tankers in the Gulf of Oman. Iran has denied involvement, and there is considerable skepticism around the world about American claims. We don’t yet know what really happened, and may not for some time. But what the attacks and subsequent fallout show — regardless of who carried them out — is that President Trump’s policy of “maximum pressure” is not working.

If Iran was behind the attacks, then American pressure has failed to bring it around for renewed talks and has instead prepared Iran for conflict. If the United States cannot provide clinching evidence of Iranian culpability, its eagerness to assign blame looks like a ruse to start a war.

President Trump may not want war, but he will get one unless he balances coercion with diplomacy. He has discredited moderate voices in Tehran who had fought for the nuclear deal and the promise of engagement with the West. Iranian hard-liners, who distrust the West, want out of the nuclear deal and argue that only show of force deters Western aggression, are ascendant.

Iranian leaders think that the United States has cheated Iran and walked away from the deal to strangle Iran’s economy, break its state and force regime change. President Trump’s goal all along has been to negotiate a more stringent nuclear deal with Iran, scuttle its missile program and reduce its regional footprint.