I believe that many people know about the hostile relationship between Iran and the United States, but what exactly makes the two countries turn against each other? I'm afraid they have to find the reason for this. If the United States does not engage in hegemonism, if Iran does not engage in self-interest, then the world will be peaceful, but unfortunately there is no if.
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Historical ties between Iran and the United States
At the beginning, Iran was actually dependent on the United States, of course, this was a choice made by Iran for the purpose of interests and development. A look at a graph will make it clear.

Image from the web
Iran's geographical location was bordered by Iraq and the Arabian Peninsula to the west and the Soviet Central Asian Plate to the north. At that time, the strength of the Soviet Union made it difficult for Iran to sit still, the war in the south seemed to be on the verge of breaking out, and the occupation seemed to be a matter of minutes. Therefore, whether from the perspective of survival and development or from the perspective of the world pattern, Iran can only choose to ally with the United States. Of course, this is also beneficial and harmless to the United States, not only can go deep into the Middle East, share a share of oil resources, attack Arab countries, but also confrontation with the Soviet Union, so this alliance is a hit.
At that time, there was a revival movement in Arabia, the main purpose was to unify the Middle East, but this goal is completely against the will of the United States, if the Middle East is unified, forming a strong subject state, then the United States has no interests to speak of, so for Iran's cooperation, the United States did not think about it and agreed, or it was long awaited. The purpose is clear, don't engage in unification, I will provide weapons support for your civil war.
Can the United States allow Iran to be attached to it for nothing? Of course not. The price is that Iran must be anti-Soviet, originally Iran also wanted to rely on the United States to take advantage, if the United States won against the Soviet Union, then they can at least get a piece of the pie, Iran's northern territory bordering the Soviet Union is the fat in their hearts. However, the Soviet Union was also a former hegemon, and even if the United States was strong, if it wanted to win this war, it would probably hurt the enemy by a thousand and lose eight hundred. Therefore, no one dares to act rashly. Iran's dependence did cause some trouble for the Soviet Union, but at the same time it also consumed a lot of resources. After entering the Cold War, the Soviet Union turned offensive to defensive, which also meant that Iran needed to face soviet pressure alone.
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A turning point in U.S.-Iran relations
The development of the post-war global economy increased the demand for oil, and the Middle East became a bountiful commodity. But the ones who benefit the most are Arab countries such as Iraq and Saudi Arabia, followed by Iran. The former has always had a hostile relationship with Iran. Later, the oil crisis broke out, the United States announced that it was decoupled from the dollar and gold, the dollar was pegged to oil, and reached an agreement with the Arab countries, which made the status of oil to a higher level. If the United States supported Iran in order to contain the Soviet Union's power in the Middle East, this is understandable. But Iran alone could not shake the Soviet Union's position. Therefore, when the Arab countries and the United States allied, Iran's status declined, which also laid the groundwork for Iran and the United States to turn against each other in the future. You know, the United States has always been a profit-driven country, not moral. You Arab countries are dependent on me, and if you go to war with the Soviet Union, I will side with you, but you will have to go ahead. But if there are contradictions within you, such as the contradictions between Iran and Iraq and Saudi Arabia, then I am sorry, I have no heart, you can solve them yourself. Isn't that a good fit for the United States?
Then Iran realized this problem, and the United States could not be trusted. Originally Iran is also a big country in the Middle East, rich in oil resources, this is the bottom of the book, and has great control over the Two Rivers Basin and the Persian Gulf, to be honest, if you take the road of independent innovation, reform and development, now they can absolutely become a world power, that unified the Middle East, recovery of Iraq and Saudi Arabia is just around the corner. They have indeed done the same, land distribution reform, privatization of enterprises, and vigorous development of education, science, culture and health, if it continues like this. But after all, it is a small country, and the confrontation with the Soviet Union and other Arab countries has already consumed a lot of resources, and some of it has to be plundered by the United States, and there are very few left for development, and this development policy will not be solved.
Iran's domestic government judges the hour and sizes up the situation, and cannot resist the Soviet Union externally and continue reform internally. The master does not help me, sorry, I have to change the master. So he chose to cooperate with the Soviet Union to a certain extent to solve the problem of external troubles, at least the people within the territory did not have to worry about the Soviet invasion every day. At this point, the United States and Iran have completely broken up, turned against each other, and will no longer interact in this life.
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The trigger for the upgrading of US-Iran relations
When it comes to the relationship between Iran and the United States, we have to say one person: Sulaimani. This is the soul of Iran. How soully is there?
Arguably higher than the prestige of the Iranian president. One can imagine his position in Iran.
Soleimani:
The top commander of Iran's intelligence and special forces, major general (Iran's highest rank), was named one of the most influential 100 people in 2017 by Time magazine in 2017. He is a combination of elite agents, well-known generals and pop icons.
The implication is that Sulaimani is not only handsome, strong in martial arts, good reputation, and high prestige.
Sulaimani's life is also relatively rich, when he was a child, he attended religious school, had a stoic and persevering personality, worked as a bricklayer, a textile worker, etc., and later joined the Iranian Islamic Revolutionary Guard Corps, responsible for Khomeini's security work, and met the later Iranian President Mohammed. Ahmadinejad, who later won the victory against Saddam Hussein's forces, gradually revealed his reputation, and then fought against drug trafficking in the country.
But this is not where he is best, the most powerful thing is his journey as the spy king of the Middle East in Iran. That's why Americans are so jealous of him.
In 2003, after the United States overthrew Saddam Hussein's regime, Sulamani seized the opportunity to send a large number of agents to infiltrate southern Iraq to confront the local army and the US army, causing heavy losses to the US army. In 2007, he plotted against Iraqi soldiers in the US military base, kidnapped and killed 5 US soldiers, and made them into a body bomb, which injured and killed the US troops who came to the rescue. Assassinated the Saudi ambassador to the United States in 2011. 12 years of providing weapons support to President Suria's security forces were sanctioned by the United States. In 2016, more than 100 CIA agents were arrested ……
Such behavior has put him on the blacklist of the US military many times. So in January 2020, after the US military received the news, it used drones to carry out air raids on Baghdad airports, and Sulaimani was subsequently confirmed to have been killed in this bombing. At this point, the anti-American movement in Iran reached its climax.
The status of oil in renewable energy is difficult to shake, and the production is limited, the goal of the US war against Iraq is oil, and it also wants to use Iraq to pry open the door of oil in the Middle East, but it is a matter of life and death, Iran will never back down, even if the world is opposed to nuclear weapons, they will do it. The position made clear to the United States is: I can win if you fight, but I will make you pay a terrible price. Therefore, in this period, it is very meaningful to agree to Iran's accession to the "SCO"!