"A look back at the assassination of Soleimani, the subsequent missile attack on 2 US bases in Iraq and the almost simultaneous shooting down of a Ukrainian passenger plane:
Far from being arch enemies, all politicians and members of the political or 'elite' class around the world have more in common with each other than they do with their respective populations. They all share the common goal of maintaining themselves in power and keeping their potentially 'restless' populations under control and relatively happy, because it is from their populations that they derive their power (and wealth).
Soleimani had become an increasingly powerful figure in both the Iranian military and Iranian political and social life over the past few years. The political class in any country is usually very wary of military leaders accruing too much power and influence, because when they do, they tend to get ideas that they can do a better job. So it's possible that Soleimani was seen as a growing threat to the Iranian government and the Ayatollah and his coterie.
Through spying and electronic eves-dropping and direct discussions with Iranians, individuals in the Trump government may have become aware of this and came up with the idea of getting rid of him in the knowledge that the Iranians would not mind so much. The thinking behind this may have been Trump's awareness that with the recent alarming spread of Iranian influence across Iraq and into Syria and Lebanon (much of it thanks to Soleimani), the Israelis were reaching the point of no return where they might initiate a real war against Iran (and the Iranian government was likely aware of this). If such a war were to occur, Trump would be forced to side with Israel, and he was not inclined to have the US embroiled in another major ME war (his 'base' of supporters in the US would not be happy). At the same time, the Iranian government does not have a death wish, and they very likely would not win such a war (Israel has 400 nukes and the psychos to use them).
Killing Soleimani may have been seen, therefore, as a good way to stay Israel's hand, appease the Zionists by showing them that Trump was looking out for their interests, while presenting himself as a leader who was taking a 'strong stance' on Iran. Notice that, in the immediate aftermath of the assassination, Trump tweeted that he did it to "prevent a war, not start one". That was perplexing to many people since killing Soleimani appeared to be the best way to START a war between the US and Iran. But perhaps the war that Trump was preventing with this action was not primarily a war between the US and Iran but between the US and Israel (then pulling the US in). Notice also that Trump felt he had to further justify the assassination to his base by claiming the Soleimani was a 'bad man' who had been responsible for killing US troops in Iraq.
From the Iranian perspective, killing Soleimani removed a threat to their power, but the Iranian government had to go through the motions of being 'outraged' and responding with the missile attack on 2 US bases in Iraq, an attack that was very likely signaled to the US beforehand. All of this was necessary because the Iranian people, as oblivious as the American people to the way global politics really works, demanded it as a response to the egregious murder of their beloved general by the 'great Satan'. The outpouring of grief and the multiple millions of people who attended the various funeral proceedings for Soleimani is perhaps an insight into the extent of the threat he posed to the established powers in Iran.
The shooting down of the Ukrainian plane was the final element, but this was most likely a 'wild card', thrown in by elements within the Israeli intelligence establishment to highlight the fact that they were not fooled by the whole spectacle and perhaps as a warning to the US and Iranian players of what they can do. As I wrote at the time, someone very likely 'messed' with either the plane or the missile system to provoke the shoot down. Given all of this, it's no surprise that the Iranian government took responsibility for the downing of that plane, and quickly made it go away."