In the past week, there has been mounting proof of attempted Iranian interference in US affairs, through cyber-attacks and phishing scams. On Wednesday, Microsoft released a statement confirming that Iranian hackers have targeted 100 high-profile people online. In a separate statement on the same day, US Director of National Intelligence John Ratcliffe said that Iran was behind threatening emails sent to Democratic Party-leaning voters meant to “incite social unrest” and “damage President Donald Trump” according to the official. Iranian cyber-warfare is not a new phenomenon. In 2013, Iran-backed hackers took control of a small dam in the suburbs of New York. A report published last month by the Alliance for Securing Democracy, a bipartisan initiative to preserve American democracy from outside interference, revealed that “Iran is becoming a significant authoritarian actor challenging democracy in the United States and Europe”. Facebook and Twitter have both shut down thousands of fake accounts created with the aim of influencing US public opinion in Tehran’s favour. This is particularly worrying in the context of the US presidential election, but these operations are not limited to this particular event. And while Tehran does not possess the same expertise and sophistication as Beijing and Moscow, some of its cyber-attacks have been successful. For instance, Microsoft said that a team of Iranian hackers called the Phosphorus group had tried to scam powerful officials around the world. The hackers posed as conference organisers in a phishing campaign targeting potential attendees of the forthcoming Munich Security Conference and the Think 20 Summit in Saudi Arabia, two events attended by world leaders and senior analysts. Victims were tricked into clicking on a link sent via email, inadvertently downloading a malicious software on their device. “The attacks were successful in compromising several victims, including former ambassadors and other senior policy experts,” said Microsoft in the statement. Such attacks are evidently illegal and destabilising, yet the Iranian government indulges in cyber-criminality on an international level with little regard to the sovereignty of other nations. Tehran, it appears, is, bent on expanding its arms arsenal, not only by enriching uranium and developing its missile programme, but also by waging cyber-warfare against other countries. The 2015 nuclear deal, from which the US unilaterally withdrew in 2018, had capped Tehran’s uranium enrichment limit. The situation has escalated between the two countries ever since, as Tehran refused to negotiate a new deal with the US. Instead of proving to the world that it is a rational actor, Iran has resorted to inflammatory rhetoric and used its armed proxies in Lebanon, Yemen and Iraq to fan the flames of sectarian violence and launch attacks against the US and its allies. These acts of reprisal have only proven that the nuclear deal was, indeed, flawed, as it did not take into account Iran’s ballistic missile programme, or its funding of dangerous proxies in the region. It has now become apparent that the agreement also failed to limit the regime’s ability to conduct cyber-warfare, the latest tool in the regime’s playbook for foreign meddling. Whichever presidential candidate wins this week’s election, they would do well to take strong action against Iran’s complete weapons arsenal, be it ballistic, nuclear or digital in nature.