The Iranian nuclear deal was always going to be one of the bitterest parts of Barack Obama's international legacy. Outmaneuvered and exhausted by Iranian negotiators during many months of talks, Obama and his Secretary of State John Kerry in the end went for a deal that was in fact no deal at all, since even had the Iranians intended to keep to their side of the bargain, the agreement would only be in place for 15 years. What Obama hailed as a diplomatic triumph was in fact a bad defeat. International sanctions had brought Iran to the brink of collapse. The Tehran regime was desperate for them to end because rising economic problems were endangering the rule of the ayatollahs. Obama thought he saw his moment. The Iranians were on the ropes. How could they not be sincere in their protests that they were prepared to talk about abandoning their nuclear program? Unfortunately, Obama did not listen to the counsel of America's allies in the Middle East, not least to the warnings from here in the Kingdom. Talks about Iran's nuclear arms ambitions should only have been the half of it. Tehran's increasing meddling in the region, in Eastern Province, in Iraq, in Yemen, Bahrain and most obviously in Syria and Lebanon was and remains an immediate threat to stability in the Middle East. If a deal was to be extracted from the hard-pressed regime in Tehran, then it had to be a comprehensive agreement that would oblige the Iranians to draw in their claws and live in peace and amity with their neighbors. But Obama was mesmerized by the nuclear deal. Now Donald Trump has to try and undo the harm. Secretary of State Rex Tillerson has pointed to "alarming ongoing provocations" by Iran, among which is the testing of missiles that could deliver nuclear warheads. Such tests were banned and the Iranians are protesting, naturally with a straight face, that the rockets they fired are not nuclear capable, even though all the evidence is that they are. Trump has vowed to review the nuclear deal and reconsider sanctions. It seems clear that he should be every bit as tough with the Iranians as he is with North Korea, not least because there is a proven link between the nuclear weapons programs of both countries. After his forthright military response to the Syrian regime's fresh use of chemical weapons against its people, the imperative for more vigorous action against Iran, which sustains Assad's dictatorship, is obvious. If Trump decides the Iranian nuclear deal must be revisited and sanctions reimposed, then it is crucial that he looks at the wider picture. Iran is intent upon destabilizing the region. Nothing Obama did in his weak and vacillating incumbency served to check or even discourage Tehran's malevolence toward Washington's loyal allies in the Middle East. It seems clear that the Trump administration must start over with Iran. The missile tests alone justify suspending the January 2016 nuclear deal. There is also compelling evidence that Tehran is welching on its commitments to freeze its nuclear weapons research at the Natanz facility and is not yet shipping out excess heavy water from the Arak nuclear reactor, as it promised. If the Geneva deal 15 months ago was another Obama red line, Iran has already crossed it.