"particularly worrisome." The price of oil was about US$40 by mid-October. In 2021, the record-high energy prices were driven by a global surge in demand as the world quit the economic recession caused by COVID-19, particularly due to strong energy demand in Asia. The ongoing 2019–2021 Persian Gulf crisis, which includes the use of drones to attack Saudi Arabia's oil infrastructure, has made the Gulf states aware of their vulnerability. Former US President "Donald Trump's 'maximum pressure' campaign led Iran to sabotage oil tankers in the Persian Gulf and supply drones and missiles for a surprise strike on Saudi oil facilities in 2019." In January 2022, Yemen's Houthi rebels drone attacks destroyed oil tankers in Abu Dhabi prompting concerns about further increases in the price of oil. The oil prices were seen rising to hit $71.38 per barrel in March 2021, marking the highest since the beginning of the pandemic in January 2020. The oil price rise followed a missile drone attack on Saudi Arabia's Aramco oil facility by Yemen’s Houthi rebels. The United States said it was committed to defending Saudi Arabia. On 5 October 2021, crude oil prices reached a multiyear high but retreated by 2% the following day. The price of crude was on the rise since June 2021, after a statement by a top US diplomat that even with a nuclear deal with Iran, hundreds of economic sanctions would remain in place. Since September 2021, Europe's energy crisis has been worsening, driven by high crude prices and a scarcity of Russian gas on the continent. The high price of oil in late 2021, which resulted in US gasoline pump prices that rose by over $1 a gallon—a seven-year high—added pressure to the United States, which has extensive reserves of oil and has been one of the world's largest producers of oil since at least 2018. One of the major factors in the US refraining from increased oil production is related to "investor demands for higher financial returns". Another factor as described by Forbes, is 'backwardation'—when oil futures markets see the current price of $85+ as higher than what they can anticipate in the months and years in the future. If investors perceive lower future prices, they will not invest in "new drilling and fracking." By mid-January 2022, Reuters raised concerns that an increase in the price of oil to $100—which seemed to be imminent—would worsen the