Notorious for his alleged role in the use of chemical weapons in Syria and the 1991 shooting of pro-democracy protesters, Vladimir Putin's appointment of Sergei Surovikin is designed to send a clear signal to Russia and the West.
A military veteran who served in the Soviet Union's ultimately doomed war with Afghanistan during the 1980s, he was appointed on Saturday as the commander of Russia's invading forces in Ukraine.
The 55-year-old is infamous for ordering troops to open fire on pro-democracy protesters in Moscow, when three people were killed during the final days of the Soviet Union in 1991.
He went on to lead Russian forces' intervention during the Syrian War in 2017.
Gen Surovikin is accused of complicity in the indiscriminate bombing of opposition fighters and of overseeing chemical weapons attacks, in a campaign thought to have been pivotal in helping Syria's government regain control over most of the country.
The consensus among experts is that Vladimir Putin's decision to have him take charge of Russia's forces in Ukraine is a direct result of his reputation for ruthlessness and brutality.
"Putin's regime has repeatedly issued threats over recent weeks of using a nuclear option. We need to think about what the capability is, the intent and the opportunity.
"So they have already signalled their intent, but they would need commanders who would have the capability to do it.
"This is a man who has used chemical weapons in recent history, so that demonstrates capability."
Putin's power struggle
Mr McKenzie said another factor in the appointment is likely to be how it will affect the power struggle around the Kremlin that many commentators suggest has emerged since the launch of Russia's troubled military campaign in Ukraine.
Gen Surovikin is seen as an ally of Yevgeny Prigozhin, the founder and head of the shadowy Wagner mercenary group, which is believed to have been active for Russia in the Donbas region of eastern Ukraine.
He has been among the most prominent hawkish critics of Russia's defence ministry while demanding an escalation of the conflict from Moscow.
"Prigozhin gave Surovikin a thumbs up on his [messaging app] Telegram channel over the weekend," Mr McKenzie said.
"So there is a strong indication that this appointment is also Putin consolidating his power among the various commanders."
And in wider terms, Mr McKenzie suggested the move would also go some way towards placating the many hawkish voices in Russia.
https://news.sky.com/story/sergei-surovikin-russias-savage-new-commander-in-ukraine-and-why-his-appointment-could-be-an-ominous-sign-of-putins-plan-12717203#:~:text=%22The%20nationalistic%20supporters,to%20Surovikin%27s%20appointment.
He told Sky News: "Pressure has clearly been growing on Putin in recent weeks from a broad range of nationalists who are asking: 'Why don't you bomb their infrastructure? Why don't you bomb Kyiv?'