One would have thought that the UN speech would give Trump a chance to explain the necessity of decertification. He could have shown why Iran is not in compliance. He could also have laid out what Iran needed to do to ensure certification. And he could have stated the strategy he proposed to pursue if he pulled out of the deal. But he did none of these things. Instead, he rattled off a list of Iranian provocations and aggressions in the Middle East, but said virtually nothing about its “non-compliance.” Instead, he charged that “the Iran deal was one of the worst and most one-sided transactions the United States has ever entered into. Frankly, that deal is an embarrassment to the United States, and I don’t think you’ve heard the last of it, believe me.”

Believe me? There was a time when the world took American leaders at their word. In 1962, at the height of the Cuban Missile Crisis, President John F. Kennedy dispatched Dean Acheson, the former secretary of state, to meet with Charles De Gaulle, the president of France. Acheson offered to share all U.S. intelligence on the Soviet missiles in Cuba. De Gaulle replied, “I don’t need to see pictures … the word of the president of the United States is good enough for me.”

What may have worked for Kennedy then does not work any more. For that, America can thank Iraq’s non-existent weapons of mass destruction. And it definitely will not work for a president with as flexible a relationship with the truth as Trump.

This speech was a gift to Iran because it hinted that the president of the United States has no case and no evidence. The day after the speech, Trump said he had decided on whether or not to certify the JCPOA, but would not yet reveal his decision. When he does so, he will not have prepared the nation or the world.

Trump always justifies his reticence to offer strategic details by saying he wants to preserve the element of surprise. This is a standard line of his since at least 1984, when he told a Washington Post reporter he had a secret plan to negotiate nuclear arms reductions with the Soviet Union that he could not reveal in the unlikely case he was asked to implement it. But, the penny is beginning to drop that, with Trump, there is no difference between unpredictability and indecisiveness. He does not know what he intends to do. So he feigns unpredictability .

The consequences of this indecisiveness and lack of preparation are real. If Trump does announce that Iran is no longer in compliance with the nuclear deal, he will then have to decide whether to re-impose sanctions on Iran. In a major speech to the American Enterprise Institute, Nikki Haley, his ambassador to the United Nations, said the administration would stay neutral on the issue and pass it over to Congress. Since the United States does virtually zero trade with Iran, Congress would face the challenge of either sanctioning non-American companies, including EU-based ones, who invest in or trade with Iran.