The shocking murder of Russian opposition figure Boris Nemtsov, literally in sight of the Kremlin, clearly marks the beginning of a new era in Russian politics and Russiawatching alike. And it is unlikely to be pretty.

Who killed Nemtsov, who was behind it? At this stage, I have absolutely no idea. The government? I find it hard to think Vladimir Putin would actually order Nemtsov killed, not because the Russian President is a pacifist but because I see no real advantage.

Already people are throwing around the parallel of the Kirov murder which at one stroke did away with Stalin’s greatest rival and gave him a pretext for purging the elite. But I don’t think Putin needs any excuses for whatever repressions he may want to carry out, and Nemtsov was certainly no threat.

Besides, for a leader whose legitimacy is in part based on the way he ended the “bespredel”, the overt and violent lawlessness of the 1990s, this happening so close to the seat of power is an embarrassment for Putin. If anything it appears to have galvanised the weekend’s protests – turning them into a commemorative event for Nemtsov.

Perhaps it over-zealous security officers doing what they thought would please the boss? Maybe, but we have no reason to believe that. Nationalists or crazies inspired by the new mood of xenophobia and witch-hunting being stoked by the Kremlin? Much more plausible. Oppositionist figures wanting a martyr or, to go to the real extremes of the crazy spectrum, US agents likewise stirring trouble? I don’t believe that for a second.

But we don’t know. We know pretty much nothing but the facts, and so we are all tempted to interpret them based on our assumptions about Russia and Putin and the world. That’s human, and inevitable, and dangerous. And it also points to the fact that this is something of a watershed, marking three things that have been processes rather than sudden events.

1. The death of neutrality

It is increasingly difficult not to be on one side or the other. We’ve already seen this over Ukraine (I’ve been castigated as a Kremlin stooge for not using the word “terrorist” to describe the rebels, and a Western shill for claiming that Russian troops are present, all for the same article!), but I think it’s also happening with Russia.

Not to regard Putin as a murderous mafioso-fascist-tyrant-kleptocrat who kills for the hell of it is to be an apologist. To refuse to believe the State Department is actively trying to install Alexei Navalny in the Kremlin makes you a tool of Western “colour revolution”. Analysis increasingly, I’m sorry to say, takes second place to assertion of the world as the observer “knows” it to be.

2. The death of ‘stuff happens’

Nothing, it seems, is not part of a plan, a strategy, a ploy or a gambit. MH17 was a Ukrainian act of misinformation to demonise the rebels (arrant nonsense). Nemtsov must have been killed by the state because he was under 24/7 surveillance (very doubtful: that would require a massive operation, out of proportion with his actual importance). The truth of the matter is that politicians and government are much less in control of events than they and we might think.

My working hypothesis is that Nemtsov was killed by some murderous mavericks, not government agents, nor opposition fanatics. But the reason they felt obliged to go and gun down a frankly past-his-peak anti-government figure is highly likely to be because of the increasingly toxic political climate that is a clear product of Kremlin agency, in which people like Nemtsov are portrayed as Russophobic minions of the West, enemies of Russia’s people, culture, values and interests.

So, to loop things round, Putin is guilty, I suspect, the same way that tobacco companies are considered guilty of cancer deaths after they may have known about the risks, or any hate-speaker may be when some unhinged acolytes take their sentiments and decide to turn them into bloody action.

So maybe I am implicitly pointing to a third casualty:

3. The death of optimism

How does a regime soothe such feverish sentiments? Indeed, can it do so? I do not believe Putin is intent on World War III, or wants to create a neo-Stalinist terror-state, or do any of the other things the more extreme critics aver. But I suspect that in the name of holding onto power (his greatest ambition) and asserting the true sovereignty of Russia (his second greatest), regardless of the opposition of liberals, Ukraine, the West, or whoever, Putin has taken a step too far along a dark and dangerous path for him ever to be able to step back or even, worst yet, stop walking forward.

Mark Galeotti is a Professor of Global Affairs at New York University. A version of this article also appears at In Moscow’s Shadows, Mark Galeotti’s own site. This article was originally published in The Conversation on 2 March 2015. It is republished with permission.