In the aftermath of the attack carried out by Iranian-backed Houthi rebels on a peaceful civilian district of Abu Dhabi this week, it is hard to see how US President Joe Biden can resist calls for the extremist group to be re-designated a terrorist organisation. As Dr Anwar Gargash, diplomatic adviser to UAE President Sheikh Khalifa, stated in the immediate aftermath of the attack, the Houthi operation was a “<a href="https://www.thenationalnews.com/uae/2022/01/17/abu-dhabi-confirms-explosion-of-petrol-tankers-in-musaffah-and-minor-fire-at-airport/" target="_blank">heinous attack on civilian facilities</a>” that amounted to nothing short of terrorism. The attack certainly constitutes a serious escalation in the Houthis’ terrorist campaign being waged against members of the Saudi-led coalition, which is seeking to restore Yemen’s democratically-elected government to power. In the latest outrage, the Iranian-backed rebels said they fired five ballistic missiles and “a large number of drones” at Dubai and Abu Dhabi airports, an oil refinery in Musaffah as well as several “sensitive” sites in the UAE. Abu Dhabi police said three people were killed and six wounded when three fuel tanker trucks exploded in the industrial Musaffah area near storage facilities run by the country’s Adnoc oil conglomerate. This week’s attack on the UAE was similar to the Houthi operation carried out against Saudi Arabia’s Aramco facilities in September 2019, which also involved a mixture of <a href="https://www.thenationalnews.com/uae/2022/01/18/houthi-terror-attack-what-drones-do-the-terrorists-have/" target="_blank">drones</a> and cruise missiles, which the Houthis were later found to have acquired from Iran. UAE officials were quick to condemn the attack against civilian facilities on Emirati soil. "(It) will not go unpunished," said a statement issued by the UAE foreign ministry. "<a href="https://www.thenationalnews.com/uae/2022/01/17/abu-dhabi-blasts-a-sinful-attack-by-houthi-militia-says-senior-uae-official/" target="_blank">The UAE reserves the right to respond</a> to these terrorist attacks and criminal escalation." Within hours, the <a href="https://www.thenationalnews.com/gulf-news/2022/01/18/saudi-led-coalition-begins-air-raids-on-houthi-targets-in-yemen-capital-sanaa/" target="_blank">Saudi-led coalition responded</a> by launching airstrikes against Houthi training camps and strongholds around the Yemeni capital Sanaa, and said it had succeeded in destroying a drone communication system. <a href="https://www.thenationalnews.com/uae/government/2022/01/18/india-condemns-houthi-attack-on-abu-dhabi-that-left-two-citizens-dead/" target="_blank">Global leaders</a> have rallied around the UAE in the wake of the Houthi attacks, with Liz Truss, the UK foreign secretary, responding on Twitter: “I condemn in the strongest terms the Houthi-claimed terrorist attacks on the United Arab Emirates”, while the US secretary of State, Antony Blinken, and the White House national security adviser, Jake Sullivan, also denounced the attacks and promised to co-ordinate a response with Emirati officials. The attacks by the Iranian-backed rebels come at a time when the Biden administration is attempting to revive the <a href="https://www.thenationalnews.com/world/us-news/2022/01/19/a-year-of-iran-talks-yields-little-for-the-biden-administration/" target="_blank">2015 nuclear deal with Iran</a> signed by the former Obama administration, and their timing will inevitably raise questions about Tehran’s commitment to the negotiations over the future of its nuclear programme. It also puts the spotlight on Mr Biden’s decision, taken in the first weeks of his presidency, to remove the Houthis from Washington’s list of designated terrorist groups, which had originally been implemented by the Trump administration. The decision to lift the designation of the Iranian-backed Houthis as a global terrorist organisation was taken as part of the Biden administration’s wider review of its relations with Saudi Arabia. Former US President Donald Trump had originally made the designation in the dying days of his presidency to try and cut off the Houthis’ funding and weapons, which are mainly supplied by Iran. Mr Biden’s decision to lift the designation was taken to help alleviate the deepening humanitarian disaster in Yemen, which has been caused in part by the Houthis, who control most of the aid deliveries. Another factor in Mr Biden’s decision was that he wanted to ease tensions with Tehran, which has close ties with the Houthis, as he sought to revive the nuclear talks. But this week’s attack against the UAE – which has long-standing defence ties with the US and plays host to around 5,000 American military personnel – demonstrates the Houthis and their backers have not abandoned their terrorist activities. It also raises serious questions about the wisdom of that decision, and led to renewed calls by senior UAE officials for Washington to re-designate the Houthis as a terrorist organisation. In the immediate aftermath of the attack, <a href="https://www.thenationalnews.com/world/us-news/2022/01/19/uae-ambassador-to-us-calls-on-washington-to-re-designate-houthis-as-terror-group/" target="_blank">Yousef Al Otaiba</a>, the UAE ambassador to the US, made contact with the Biden administration and Congress asking for the Houthis to be re-designated as a terrorist organisation. “We are asking our friends in the administration and in Congress to reinstate the Houthi terrorist designation," Mr Al Otaiba said at the Jewish Institute for National Security of America. Sheikh Mohamed bin Zayed, Crown Prince of Abu Dhabi and Deputy Supreme Commander of the Armed Forces, also held talks with US Defence Secretary Lloyd Austin concerning the attack, when they discussed ways to boost military and security co-operation between the UAE and the US, and the need for a "decisive international stance" in countering Houthi attacks. The issue is certainly being taken seriously by Mr Biden, who confirmed the matter was being discussed by officials during a press conference that was held to mark his first year in office. When asked whether he was considering re-designating the Houthis as a terrorist organisation, Mr Biden replied: “It's under consideration, yes.” For the moment, though, the Biden administration’s main focus appears to be trying to arrange a ceasefire in Yemen’s long-running civil war as <a href="https://www.thenationalnews.com/gulf-news/bahrain/2021/11/21/tim-lenderking-the-us-is-committed-to-helping-yemen-towards-a-peaceful-future/" target="_blank">Tim Lenderking</a>, Mr Biden’s special envoy for Yemen, departs for talks in London and the Gulf. A State Department spokesman said the visit will largely be aimed at pushing for a ceasefire that would allow all parties to take steps to improve humanitarian access. “Ending the war in Yemen takes the two parties that are involved in it and it's going to be very difficult,” said Mr Biden. Even though the Biden administration has lifted the terrorist designation against the Houthis, it has still maintained and expanded sanctions against individual Houthi leaders, including Abd Al Karim Al Ghamari and Yusuf Al Madani, as well as senior Houthi military officer Saleh Mesfer Al Shaer. The Treasury Department has also sanctioned Iran-based Houthi financier Said Al Jamal. But the administration is likely to come under pressure from Congress to take a harder line, both with the Houthis as well as their backers, which could have serious implications for the future of the Iran nuclear talks. Apart from calling for the Houthis to be re-designated a terrorist group, Republicans in Congress are calling for further sanctions against Iran and additional arms sales to the Gulf – measures that, if implemented, would make the prospects of reaching a nuclear deal with Tehran even more remote.