<P> The election of Donald Trump in the United States in 2016 has prompted uncertainty from both countries about future US policy in the Middle East, as both were targets of criticism during his campaign . The Saudi government anticipated that the Trump administration would adopt a more hawkish stance than the Obama administration on Iran, which would potentially benefit Riyadh . Iran feared the return of economic isolation, and President Hassan Rouhani made efforts to establish further international economic participation for the country by signing oil deals with Western companies before Trump took office . </P> <P> In May 2017, Trump declared a shift in US foreign policy toward favoring Saudi Arabia at Iran's expense, marking a departure from President Obama's more reconciliatory approach . This move came days after the re-election of Rouhani in Iran, who defeated conservative candidate Ebrahim Raisi . Rouhani's victory was seen as a popular mandate for liberal reforms in the country . </P> <P> Several incidents in mid-2017 further heightened tensions . In May 2017, Saudi forces laid siege on Al - Awamiyah, the home of Nimr al - Nimr, in a clash with Shia militants . Dozens of Shia civilians were reportedly killed . Residents are not allowed to enter or leave, and military indiscriminately shells the neighborhoods with artillery fire and snipers are reportedly shooting residents . In June, the Iranian state - owned news agency Press TV reported that the president of a Quran council and two cousins of executed Nimr al - Nimr were killed by Saudi security forces in Qatif . During the subsequent crackdown the Saudi government demolished several historical sites and many other buildings and houses in Qatif . On 17 June, Iran announced that the Saudi coast guard had killed an Iranian fisherman . Soon after, Saudi authorities captured three Iranian citizens who they claimed were IRGC members plotting a terrorist attack on an offshore Saudi oilfield . Iran denied the claim, saying that those captured are regular fishermen and demanding their immediate release . </P> <P> In the wake of the June 2017 Tehran attacks committed by ISIL militants, the Iranian Revolutionary Guard Corps issued a statement blaming Saudi Arabia, while Saudi Foreign Minister Adel al - Jubeir said there was no evidence that Saudis were involved . Later Iranian official Hossein Amir - Abdollahian stated that Saudi Arabia is the prime suspect behind the Tehran attacks . The commander of IRGC, Major General Mohammad Ali Jafari, claimed that Iran has intelligence proving Saudi Arabia's, Israel's, and the United States' involvement in the Tehran attack . Iran's Supreme Leader Ayatollah Khamenei later accused the United States of creating ISIL and of joining Saudi Arabia in funding and directing ISIL in addition to other terrorist organizations . </P>

The cold war between saudi arabia and iran