The Middle East region has always been a crossroad of interests for big powers including the USA, Iran and Russia. It should be noted that the countries in the region are also actively involved in cooperation with at least one of these big powers. The Middle East region is an extremely rich oil territory and has a very important strategic position.
This is the biggest reason why all these states lead a furious confrontation with one another. None of them would refuse to have access to the Mediterranean, Black sea and other strategically important roads. The dominance in the region can be beneficial, not only in terms of economical profits, but also in terms of military hegemony.
The confrontation does not exist between only Iran and Saudi Arabia...
The US involvement in the region stems from the fact that Iran puts all its energy into become a leader and dominant, which in turn is unacceptable since the USA and Iran are absolute rivals. It is clearly noticeable that neither during the period of Barak Obama, nor during the presidency of other US presidents, the relations with Iran have not been so warm. Donald Trump’s strategy of foreign policy is not different from other US presidents.
It is more likely that the USA leads a war with Iran, using its influence on the states of the region; in this case, it is Saudi Arabia. Iran and Saudi Arabia have long been claiming a leading role in the region; but lately, relations between the two countries have seriously worsened. Saudi Arabia, with a predominantly Sunni population, is considered the birthplace of Islam. In addition, it is also one of the world's leading oil exporters and one of the richest countries in the world.
Saudi Arabia fears that Iran can assume a dominant position in the Middle East and in every way hinders the growing influence of this Shiite country in the region. Donald Trump supports Saudi Arabia in this issue and tries to level Iran’s influence. At the same time, Saudi leads battles against Houthis rebels in Yemen and asserts that Iran provides financial assistance to them. In addition, King Salman supports the rebels in Syria and seeks to overthrow Bashar Assad, Iran's main ally.
Iran’s population (80 million) mostly consists of Shiite Muslims, and the country is considered the leading Shiite power in the region. Some experts emphasize the religious root of the problem existing between Iran and Saudi Arabia, but political reasons of confrontation are more likely to be the truth.
Each of these states has its own ally and interests. Iran does not want the USA to be a lawmaker in the region. Russia and Syria have common interests which correspond with the plans of Iran. Over the past 10 years, Iran's influence in the region has increased dramatically, especially after the overthrow of Saddam Hussein's regime in Iraq.
The USA, over the last 10 years, has strengthened its relations with Saudi Arabia which is, after Israel, its main ally in the Middle East. It would sound strange, but even Israel warms its relations with Saudi to battle Iran. Of course, Turkey is one of the main figures in the North Atlantic Treaty Organisation (NATO), but Turkey’s shaky foreign policy made the USA choose a new ally against Iran.
Turkey’s deterioration of relations with the USA was good news for Russia. Putin is passionate about creating a new block of four, to include Turkey. Historically, Turkey had better relations with the USA than with Russia. This can be supported by the fact that Mustafa Kemal Ataturk (founder of the Republic of Turkey) always prefered the western norms and laws, and used these norms in domestic and foreign policy.
Russia is the only state which manages to remain an ally of both Saudi Arabia and Iran. It has close economic ties with each of these countries; in addition, Russia sells arms to both countries. Russia's involvement in Middle East affairs has been preserved since the Cold War, when the Soviet Union supplied Syria with weapons and trained its officers.
Israel plays an inseparable role in the region, even though it does not have relations with many Arab countries. It has diplomatic relations only with Egypt and Jordan. Iran and Israel are considered irreconcilable enemies. Iran denies the right of Israel to exist and calls for the destruction of the state. Israeli Prime Minister, Benjamin Netanyahu, has always actively encouraged the international community to prevent Iran from acquiring nuclear weapons and to cancel a nuclear deal with Tehran, in order to curb its aggressive policy in the region.
According to Netanyahu, cooperation has been established with a number of Arab countries with a view to hindering the growth of Iran's influence in the region. In turn, Saudi Arabia denied reports that appeared in the Israeli media that in September, one of the Saudi princes secretly came to negotiations with Israel.
In conclusion, we can understand that the confrontation does not exist between only Iran and Saudi Arabia, but it has involved so many states; and in this case, we can speak about the collision of blocks rather than states. Some members of these blocks are interested in economic profits while others are craving political influence.