Due to the strategic and geo-economic importance of the Persian Gulf in the big powers' strategy, this paper is trying to address the US role in the security model of the Persian Gulf based on time periods and doctrines of the US presidents since 1969.

A) 1969-1974: The Nixon Doctrine

After the UK withdrawal from the East Suez in 1968, the subject of the US substitution as the Persian Gulf security provider heated up. But due to its engagement in the Vietnam war and impossibility of direct presence in the Persian Gulf arena, the US undertook a bi-pillar policy by relying on its two allies, Iran and Saudi Arabia, as economic and military pillars, under Richard Nixon. in other words, since Nixon and Kissinger were of the opinion that strengthening Iran militarily would stabilize the Middle East, Nixon appointed Iran as protector of the US vital interests in the Persian Gulf since 1970.

B) 1974-1977: The Ford Doctrine

His foreign policy was a continuation of the Nixon Doctrine, because both benefited from Kissinger for planning foreign policy. He followed up on the policies of detente with the Soviet, improvement of ties with China and US support for South Vietnam. He preserved and deepened arms ties with Iran and his major goal in the Middle East was protecting the allies against the USSR threats.

C) 1977-1981: The Carter Doctrine

following the Soviet invasion of Afghanistan in December of 1979, in January of 1980, Carter made a speech and stated that any efforts to control the Persian Gulf would be considered as an invasion to the vital US interests that would be warded off by any means such as military force. This statement was a fundamental change in the US foreign policy. The Persian Gulf had a strategic status in the Carter Doctrine and the US played a direct role in defending the Middle East  to thwart the Soviet control over the region. The Carter Doctrine led to the formation of the Rapid Deployment Force in the region. Indeed, Carter adopted the Brzezinsky formula, maintaining that the Middle East and South Asia were prone to the USSR adventurism, and reacted accordingly.

D) 1981-1989: The Reagan Doctrine

during his term the US was faced with two crises in the Persian Gulf. Confidential Deal "Arms For Hostage" ,( Iran-Contra) and the Tanker War, in which the Kuwaiti tankers came under the US flag. In other words, Reagan continued the Carter Doctrine which was strengthening the regional security and pursuing military goals. during his years of presidency, Reagan adopted a more offensive policy and was ready to challenge any regime or organization that would threat the US and its citizens. Also, transfer of arms to the region, especially to Saudi Arabia,  ramped up. Also during the Iran/Iraq war, because of the US interests being threatened, the Reagan policy revolved around three maxims: 1) exerting international pressure to end the war and preventing its spread; 2) helping the friends to protect themselves against the Iran threats; 3) cooperation with the Persian Gulf Cooperation Council states and other allies against Iran, to protect shipping under the US flag in the Persian Gulf

E) 1989-1993: the Busch Doctrine

by regard to the collapse of many communist regimes and the USSR in the early 1980s, the Middle East policies of George Busch was influenced by this new world order and the only issue which could challenge the US in the Middle East was oil. Therefore, the US priority was the peace process and Aslo Accords, and its access to the Persian Gulf oil. To protect its access to oil, he continued the policy of balancing Iran and Iraq. In his speech about his agenda in the Middle East, he stated: we will preserve our forces in the region and broaden bilateral security arrangements and preliminary materials and equipment and hold joint drills for defending sovereignty, independence and integrity of our partners in the region. We will continue our work to gain the assurance of access to oil, prevention from resorting to wars, terrorism and overthrowing , and execution of the UNSC resolutions. Two main points of his presidency were his too much closeness with Gurbachev  and the Persian Gulf War. Busch increased the number of US forces to fill the void of likely Iraqi deletion, and preventing the  Persian Gulf region's balance tilting towards Iran and conducted the operations for liberating Kuwait  and defeating Iraq in this war. This victory was the pinnacle of his career.

 F) 1993-2001: The Clinton Doctrine

The first year of his office can be conceptualized as de-regulation on the international stage, that is a period during which there are new actors, capabilities and alignments , but still no new laws. In His national security strategy, he stated: The Us has sustainable interests in the Middle East, especially access to peace in the Middle East and assurance for Israel and Arab friends' security and preserving free flow of oil with proper prices. The main part of his strategy in the Persian Gulf was based on dual containment , aimed at containing  Iran and Iraq governments as backlash states. The main focus of Clinton's administration in the Persian Gulf was reducing the chances of any threat against the Persian Gulf states and helping these states in collective defense .

G) 2001-2009: The George W. Busch Doctrine

 Following the 9/11 attacks, the span of the foreign policy subjects broadened, and in the night of 9/11 he stated that the US would punish those responsible for those cowardly attacks. In other words, the US expressly focused on the planners of the attacks, that is Al Qaeda and its leader Osama Bin Ladin. The span of war on terrorism spread  on September 17, 2001 and Busch stated that " now focus is on Bin Ladin.. and his organization. But there are other terrorists in the world . there are people who hate freedom. This is a fight for freedom." and this made for a good pretext to invade Iraq. Over time, the US, as occupier, tried to transfer power to the new Iraqi government and held training for  counter-insurgency , counter-terrorism, civil and humanitarian issues , which required  heavy military presence . During his reign the US goal was ending terrorism and focusing on international law and order.

H) 2009-2017: The Obama Doctrine

At the end of 2011, all US military units left Iraq, due to various reasons such as reducing economic expenses arising from war. Military withdrawal from Iraq was brought up by Barak Obama in his administration's big policy in 2008 under the title " The Pivot Towards Asia". In fact, during 11 years of countering terrorism, it had been taken notice of. The rise of China, India's global ambitions, non-settlement of rifts between North and South Korea and the necessity for assuring the strategic and historical allies like Japan and Australia led to US inclination to the Pacific in 2011. However, based on what the US foreign ministry published in 2014, the US still maintained its military presence  in the Persian Gulf, in which regard reasons such as preserving the security of the US allies and containing the threat of backlash states and preserving the Hormuz Strait security can be enumerated. Also, after 22 months of formal negotiations  between Iran and the 5+1 countries, the JCPOA was ratified on July 14, 2015 and was enforced on Jan 16, 2016.

I) 2017-2021: The Trump Doctrine

During the Trump term, Saudi Arabia became the axis of the US approach in the Persian Gulf, in a way that Trump's first international trip was to Saudi Arabia in May of 2017. He, too, adopted the similar Obama logic in his national defense strategy in 2018 and considered the main challenges to the US security the revisionist powers of China and Russia. On the international stage, he pulled out some of US forces from Iraq and Syria, withdrew from the JCPOA and imposed strict economic sanctions on Iran. To the opinion of the analysts, the unilateral withdrawal from the Iran nuclear deal was one of his biggest strategic mistakes in the Middle East after the Iraq war in 2003, whose consequences are to stay for many years. in September of 2020, in line with the Maximum Pressure Policy on Iran, the normalization accords between Israel and Bahrain and the UAE were signed in the White House and Trump called this the "Dawn of a New Middle East". It must be noticed that despite emphasis on China and Russia, the US is still the dominant power and guarantor of Israel and Persian Gulf Arab states' security. To the analysts like Anthoni Kordesman from the CSIS think tank, Trump's four year foreign policy led to more destabilization and insecurity in the Persian Gulf, and Biden must take measures to create new structures and frameworks based on deterrence and defense and success in this regard is conditioned to solving issues  like extremist groups like ISIS, the Iran nuclear issue, the Israeli-Palestinian issue, and reconstructing US security cooperation with the Arab states of the region.

J) 2021- Now: The Biden Doctrine:

With less than a year of the age of Biden's administration , the general assessment of his Persian Gulf Foreign Policy is not clear, but it can be said that his foreign policy, rhetorically and stylistically, is somehow the return and continuation  of Obama's policy. During his electoral campaign, he employed a critical approach towards Washington's old partner in the Persian Gulf, that is Saudi Arabia, and asked for ending Saudi support for the Yemen War and blamed Muhammad Bin Salman for the assassination of the Saudi journalist, Jamal Khashoggi . About Yemen, he is asking for more humanitarian aid to the refugees, compared to the previous term. About Israel, new support for the Palestinian government could strengthen some new accords between Israel and its neighbors. In Iraq, in 2003, Biden was among the senators who supported Busch's invasion of Iraq. But in 2007, he opposed the increase of  US forces and attacks and was a fan of the Extra Counter-Terrorism Strategy which took shape during the Obama administration to counter the Jihadi and military groups across the world. The biggest pivot in Biden's foreign policy  in the Middle East and Persian Gulf is focus on Iran, which is the effort to get back on the track of diplomacy and a nuclear agreement.

  Fatemeh Mohammadi, Expert at IPIS Center