I don't know why my post is removed despite of that I try explain it more.
If you look to history of region, you see that three countries took control of most part of the world and Middle East in different times.
Iran: Before Islam
Saudi Arabia: After Islam
Turkey: Ottoman time.
And now all those countries have dreams about their golden ages and have competition with the others to take control of Middle East in their hands.
Between those three countries Iran has different conditions.
Energy reservoirs, mineral depositions, strategic situation, population, cultural ties with all peripheral countries and agricultural conditions give Iran unique position compare to the others. Turkey doesn't have access to Persian Gulf, doesn't have energy resources and almost people in there are Turk and Kurd. Saudi Arabia doesn’t have access to Caspian Sea area, doesn't have important mineral depositions and doesn’t have powerful agriculture with majority of Arab people. However Iran’s people are Fars, Turk, Kurd, Arab, Baloch, Turkman, Armenian and many others (including other Christians and Jewishs).
I think that Iran's will to control of region, started in 1970s. Iran (or I should say Shah) took leadership of OPEC and they fought for oil price. Among this fight, Mr. Nixon made the petro-dollar deal with Saudi Arabia and other OPEC countries but OPEC (Shah?) won the war at 1974 and oil price rise dramatically. I believe that fundamental of problem between Iran and US was made in that time. And after that US worried about Shah's plans.
Iran started developments plan in all directions. Iran's nuclear program started with help of US and Germany. Iran's army developed rapidly (with particular attention to Air Force) and growth of Iran's economy rose to between 10 and 20 percent for a decay (with producing 6 million-barrel oil per day).
And then Iran started to play a major role in region.
At 1973 Iran started to send troops to Oman to defeat rebellions and the Iranian troop remained in there till Iran's revolution.
Iran's problem with Iraq led to a military conflict and Iraq was defeated in two days. The military conflict led to 1975 contract that was signed by two countries in Algeria. It's interesting that Saddam Hussein signed contract from Iraqi side and in 1980 he ripe off the contract.
Then in last years of 1970s Iran became most important and most powerful country of Middle East, in the time that all countries of region heavily suffered from undeveloped conditions.
Shah got more and more disobedient. He started to establish a military relationship with USSR and bought some armored vehicle from USSR.
To get everything worse, Shah started to crisis west and claims that western countries should change their people life style and they should work harder.
All of these led to Guadeloupe conference.
I think background of decision that was made in Guadeloupe returns to 1953 (Ajax Operation). In That year, CIA made a coup against democratic elected Prime Minister Mohammad Mosaddegh to return Shah to power with help of Islamists, Mobs and some part of army. The coup was successful, but in that time US made fool Ayatollah Kashani and after coup he loses all of his influence.
In last years of 1970s US think that "why we cannot repeat the successful experience of corporation with Islamist?" They thought that this time they could remove Shah from power and then helped to moderate nationalist Islamic parties (Technocrats) to take power (The party that was reborn after coup from remain of the other party that heavily suffered from the coup – Nehzat Azadi). Consequents could be something like this: disobedient Shah would have been removed from power and again an obedient Iran with technocrat’s leadership (educated in west) remains in Western Bloc.
Then Guadeloupe decision was made and Iran faced revolution.
But this time everything has changed to compare 1953. Cleric people in Iran didn’t forget that what happened in 1953. Imam Khomeini was far far smarter than that Americans supposed. After revolution, for preventing from something that was happened in 1953, US embassy was captured by Muslim Students Follower’s Imam Line and Iran Hostage Crisis was started on November 4 1979. Only after Hostage Crisis, Mr. Carter realized that Iran was out of control. And after that US did everything to return Iran to Western Bloc but failed completely.
Operation Eagle Claw on April 24 1980
Nojeh Coup on 9-10 July 1980
Iraq Attack on 22 September 1980 to August 1988.
Support Iraq in war in anyway
Downing Iranian Airbus on July 3 1988 with 290 civilians dead
Sanctions because of everything
And finally Mr. Trump
Against that Iran did something bad to US too as revenge.
All these not only didn’t get back Iran to Western Bloc but also caused Iran more and more was pushed toward Russia and China.
And now an independent Iran, most stable and most democratic country in middle of disturbed Middle East with close ties with Russia and China, is worst thing that US could imagine.