Enough time has elapsed since Prigozhin met his end in a plane crash northwest of Moscow that we may be safe in speculating a bit further on causes and motives. Further, I'm satisfied that this was a case of sabotage--probably explosives in the landing gear wells in the wings--rather than a simple shoot down. It was a “hit”. Still, the details—and, especially, who was behind it—must remain speculative. There are, at least at this point, multiple possibilities that cannot be ruled out.
The first thing we need to be clear about is who Prigozhin was--and, a closely related matter, what Wagner PMC was.
Prigozhin himself was a criminal, a street criminal in his early days. He leveraged his way into becoming an "oligarch", a mafia style businessman, fronting for Wagner--a Private Military Company. Make no mistake about it. Wagner was a business, and a highly profitable one. It took in billions every year from dealings with the Russian state, but also from a range of ventures outside Russia. That business took Wagner to unstable and corrupt parts of the world, where business practices could be rough and tumble.
Over the years Prigozhin made many enemies: In Russia, in the Russian military and security services, in Ukraine, in the West, in other parts of the world. While any of those enemies could have been responsible for the sabotage of Prigozhin's jet, it remains that the act took place in Russian territory and in circumstances that would logically have limited access to the jet. Persons with official ties to the Russian state would, just as logically, be the persons with the most plausible opportunities to sabotage the jet.
The Russian state most assuredly had motives for wanting Prigozhin out of the way. Prigozhin was a thorn in the side of the Russian military. Whether any of his claims and criticisms of the professional military had merit is beside the point--that they were repeatedly made publicly during a time of armed conflict, an existential conflict with a NATO proxy, made the smooth functioning of the Russian military more difficult. Coming from a man with no military background whatsoever—but with a criminal background—would certainly have rankled the military brass.
The Wagner mutiny took matters to a higher level. There had been rumors before the mutiny occurred that Prigozhin had been in contact with Western intelligence operatives in Africa, and Prigozhin had begun asserting loudly and publicly that the Special Military Operation was a failure and without basis. This was at a time when Wagner forces were engaged in the most high profile battle of the SMO, at Bakhmut. The mutiny unquestionably took matters to the level of treason--Wagner forces shot down a number of Russian military aircraft and killed something like 12 members of the Russian military.
In the aftermath of what turned into a bit of a farce--except for the casualties--President Putin refrained from ever using Prigozhin's name. However, he clearly characterized the mutiny as a "betrayal" and a "stab in the back." This from a man who has famously stated that betrayal is, for him, the unforgivable sin. Putin stated to the nation that those responsible for the mutiny would "pay the price." Nevertheless, in view of the extreme seriousness of the events, Putin appeared to be showing remarkable leniency, despite the gravity of his statements.
Now, as to what has been happening behind the scenes, we can only speculate. The process of clipping Wagner's wings and bringing it under the control of the Russian military did begin immediately after the mutiny was squelched--clearly, all was not forgiven. Personnel changes in the Russian military--some high profile--have been made, including among officers who had been in regular contact with Wagner. Finally, beginning shortly before the downing of Prigozhin's jet, steps were taken--and have accelerated since the downing--to wind up Wagner's overseas ventures. The most reasonable explanation is that Wagner operations in Africa were getting in the way of the official operations--diplomatic and otherwise--of the Russian state.
Lastly we come to Putin's own public reaction to the downing of the Prigozhin jet and Prigozhin's death. Prigozhin's public approval had suffered drastically in the wake of the mutiny. Putin's reaction on this occasion was matter of fact. He expressed condolences to the families of the victims but expressed no particular regret as to Prigozhin's death, remarking instead that Prigozhin had "made many mistakes." Perhaps most pointed were the remarks of a Putin ally, Chechen leader Ramzan Kadyrov, who said that he had asked the mercenary chief "to set aside his personal ambitions. But lately he either did not see or did not want to see a full picture of what was going on in the country". That fits in with reports that Prigozhin had begun attempting to reassert Wagner business interests in Africa, against the wishes of the Russian state--which would certainly include Putin.
All of this makes a Putin role--perhaps the key role--in the hit on Prigozhin plausible. When Putin first took up the reins of government in Russia he made no secret that he was determined to rein in the powerful oligarchs. Many oligarchs who were not willing to accept the new legal framework left Russia, and are championed in the West even as they live lives of luxury off their looted billions. Prigozhin had thrived under the new Putin rules but, as Kadyrov suggested, he appears to have seen the war in Ukraine as an opportunity to enhance the Wagner brand for his personal benefit--and didn't draw a line when it came to betrayal of the nation.
Militating against this working hypothesis or plausible explanation is Putin's well known devotion to legal forms—he is a lawyer, and has pursued legal reform throughout his career in office. Throughout the Special Military Operation in Ukraine Putin has adhered strictly to Russian law in his use of draftees, etc. He has also expressed a determination not to allow this crisis in Russia's history to affect its legal form of government. A "hit" of this sort would certainly be an extra-legal action, since Putin has never formally declared war and therefore hasn't instituted martial law. In such circumstances, one would have expected a trial. My argument for why Putin may have authorized or acquiesced in an extra-legal removal of a troublesome figure would run as follows.
Prigozhin was a known criminal who had, in full view of the nation, committed treason. He had received lenient treatment under the law thus far, probably to avoid national upset in a time of war. But, in spite of the lenient treatment he had received, Prigozhin had shown a lack of willingness to reform his ways. In the circumstances--Russia in the midst of an existential conflict with the American Empire, through America’s Ukraine proxy--a trial might be an undesirable national spectacle and distraction, detracting from the desired unity of national purpose in a time of war. Therefore a decision was made to put an end to the Prigozhin soap opera once and for all. Who's to say that similarly drastic actions haven't been taken by our own Deep State, for less justifiable reasons?
I'm aware that some have claimed that Putin would never have allowed this action to be taken--whether he directly authorized it or acquiesced to the urgings of, say, the FSB--at a time when Russia was celebrating its historic victory at Kursk. But Putin has shown at other times that he will take action when he thinks the time is right and when the action is required. So, for now, this is my working hypothesis.
Love the old Churchill quote in this context:
"“Kremlin political intrigues are comparable to a bulldog fight under a rug. An outsider only hears the growling, and when he sees the bones fly out from beneath it is obvious who won.”
WSJ article makes me inclined towards Putin:
https://archive.is/20230827174151/https://www.wsj.com/amp/articles/prigozhin-wagner-plane-crash-last-days-2c44dd5c