Since Iran's Islamic Revolution in 1979, the country's Shia theocracy has attempted to assert itself as the legitimate religious and political leadership of all Muslims, contesting a status that has generally been understood as belonging to Sunni-majority Saudi Arabia, where the cities of Mecca and Medina are located.

During the presidency of Akbar Hashemi and Mohammad Khatami, Iranian foreign policy switched to reducing international tensions and Iran tried to normalize its relations with its Arab neighbors.

The most significant factor was the United States administration's decision to invade Iraq in 2003, which led to the fall of Saddam, a Ba'athist Leader with pan-Arab sympathies who was determined to balance Shi'a Iran's regional influence.

During the early days of the Iranian Revolution, Ayatollah Khomeini endeavored to bridge the gap between Shias and Sunnis by forbidding criticizing the Caliphs who preceded Ali.

However, the influence of Iran on Shiite communities outside its borders and the territorial disputes with Arab neighbors among other issues remain sources of tension in Arab-Iranian relations.

[12] After a decade, in early September 2000, diplomatic and trade relations between Algeria and Iran were re-established in a decision made by Iranian President Mohammad Khatami and his Algerian counterpart Abdelaziz Bouteflika on the sidelines of the United Nations Millennium Summit.

[14] Relations continued to strengthen rapidly after that to the extent that in 2002 Iranian Defense Minister Ali Shamkhani and Algerian Joint Chief of Staff Muhamed al-Imari Wednesday signed an agreement for military and technical cooperation in Iran.

The coup would have installed a Shia cleric exiled in Iran, Hujjat al-Islam Hādī al-Mudarrisī, as supreme leader heading a theocratic government.

In August 2015, Bahraini authorities announced arresting of five members of a terrorist group which was linked to at least one bombing attack in Bahrain[20] and was believed to accept aid and training from Lebanese Hezbollah and Iran-based Revolutionary Guards.

In the same year, Princess Fawzia of Egypt, the sister of King Farouk I, married Mohammad Reza Pahlavi, the then crown prince (later Shah) of Iran.

The relationship between Cairo and Tehran became so friendly that the Shah of Iran (Persia), Mohammad Reza Pahlavi, called Sadat his "dear brother."

Furthermore, in 1979, Anwar Sadat infuriated the new Iranian government by welcoming Mohammad Reza Pahlavi, the exiled Shah of Iran, for a short, but indefinite, stay.

The impact of the war was devastating to relations in the region; general Arab support for Iraq and a fear of Shia Muslims led to many disputes between Iran and the other Persian Gulf states.

Iran also has close ties with the Lebanese political party Hezbollah and its militia force[37] to whom it reportedly provides as much as $100 million in supplies and weaponry per year.

[41] Iranian President Mahmoud Ahmadinejad planned to visit Lebanon in October 2010, amidst controversy and pressure from the United States, Israel, and a section of the March 14 alliance such as Samir Geagea to cancel the trip.

The March 8 alliance's parliamentary leader Michel Aoun, Hezbollah's Deputy Secretary General Sheikh Naim Qassem and former Lebanese Prime Minister Salim Hoss supported his visit.

[43] In June 1987, President Maaouya Ould Sid'Ahmed Taya severed all diplomatic relations with Iran in protest of the nation's supposed refusal to negotiate an end to the Iran–Iraq War.

Previously, on 27 February 1980, Iran gave formal diplomatic recognition to the Sahrawi Arab Democratic Republic as the legitimate government of the territory of Western Sahara.

Unlike the majority of its Gulf neighbors, Oman managed to uphold diplomatic relations with both sides during the Iran–Iraq War from 1980 to 1988 and strongly supported UN Security Council resolutions to end the conflict.

Most recently, the Gulf neighbors signed an initial agreement to begin supplying large quantities of natural gas from Iran to Oman, a project that was earlier reported to be worth between $7–12 billion.

[50] Following the outbreak of the Iran–Iraq War, Iranian pilgrims held a political demonstration about Saudi moving in the direction of the United States and do not take any action against Israel during the Hajj in Mecca.

"[52] In 2010, the website WikiLeaks disclosed various confidential documents pertaining to the United States and its allies which revealed that Saudi Arabian King Abdullah urged the US to attack Iran.

The Mina disaster inflamed tensions between regional rivals Saudi Arabia and Iran, which were already elevated due to the wider turmoil in the Middle East.

The Somali prime minister accuses these countries of wanting more conflict in Somalia, which seems contradictory because of the transitional government's inability to extend authority beyond Baidoa, which is something the Islamic Republic sees.

In a joint news conference with al-Bashir on 24 April, Ahmadinejad explained to the public his belief that "expansion of ties between the two countries serves the interests of both nations, the region, and the Islamic world, particularly in terms of boosting peace and stability."

Before the conference ended, al-Bashir congratulated Iran for its successful pursuit of "nuclear power for peaceful purposes," while Ahmadinejad restated his opposition to the participation of UN Peacekeepers in Darfur.

During the Iran–Iraq War, Syria sided with non-Arab Iran against its enemy Iraq and was isolated by Saudi Arabia and some of the Arab countries, with the exceptions of Libya, Lebanon, Algeria, Sudan and Oman.

[62] On 16 June 2006, the defence ministers of Iran and Syria signed an agreement for military cooperation against what they called the "common threats" presented by Israel and the United States.

Currently, Iran is involved in implementing several industrial projects in Syria, including cement factories, car assembly lines, power plants, and silo construction.

[78] Recently, despite the spread of false information by neighboring countries and outsider powers, UAE has been seeking to ease tensions with Iran, as they are two of the most strategic partners in terms of economy and politics.