First Syria and Chechnya, and now Ukraine — experts have already drawn many parallels between the Russian approach to conflicts in those areas.

Hanna Notte, a senior research associate with the Vienna Center for Disarmament and Non-Proliferation, focuses on security issues and arms control with a particular emphasis on where those intersect when it comes to Russia and the Middle East.

DW spoke to Notte about parallels she has observed in conflicts in Syria and now in Ukraine, and how that may help predict what happens next in Ukraine.

DW: You have identified parallels between the military campaign that Russia conducted in Syria and what it is doing n Ukraine. What are these?

Hanna Notte: The five parallels that I identified are starting with the idea of Russia engaging in sequential warfare, or war in phases.

Secondly, its tactic of encircling cities, conducting sieges and bombardments, but then also establishing, and I quote, "humanitarian corridors." These, I think, must be taken with a grain of salt.

The third parallel is the whole issue of foreign fighters, which is complex and multilayered because Russia both accuses the other side of using foreign fighters, then uses them itself.

And the fourth and fifth parallels bring us back to the issue of disinformation regarding the enemy's use of human shields.

Russia has often accused terrorists in Syria of using civilians as human shields. Now it's claiming the same thing about the Azov battalion in Mariupol. It also uses disinformation about the other side staging so-called "false flag" chemical attacks.

But again, while we see these parallels in specific tactics, it is always important to keep in mind the differences between Russia's campaigns in Syria versus Ukraine, which are significant in terms of objectives and the military scale of the campaign. The stakes for Russia are still quite different.

What exactly is sequential war?

In Syria, what we saw was that the Assad government and the Russian military at various points in the war — let's remember, Russia intervened in September 2015 — halted the fighting in parts of the country in order to turn elsewhere. So, in early 2017, they instituted so called de-escalation zones in western parts of Syria, which freed up resources for the Assad government to take further territory towards the east, but also to regroup, to replenish resources. And then, in 2018, the Syrian military, backed by Russia, came back and retook those de-escalation zones with the exception of Idlib, which to this day remains outside the control of the Syrian government.

In Ukraine, Russia announced that the first phase of the special military operation was concluded and that it is now focusing on the "liberation", I quote, of the Donbas. And indeed, there was withdrawal of Russian troops from the outskirts of Kyiv and from northern Ukraine.

My point with drawing attention to this parallel is not so much to suggest that we will see a similar sort of sequencing and phasing but it's merely to caution against undue optimism or the assumption that just because they're saying they'll now focus on the Donbas, we can breathe a sigh of relief and think that the fighting in the rest of the country is over.

The attempts to build humanitarian corridors for civilians to leave besieged areas, especially in Mariupol, have failed many times. From the Russian military perspective, what is the strategy here?

Yes, unfortunately the Syria precedent would again suggest that these kinds of corridors have to be taken with a lot of caution for various reasons.

A good example is the siege of Aleppo, a major city in Syria, in 2016. It was under siege for, I believe, over six months. And there  Russia also eventually opened humanitarian corridors but these were often distrusted by civilians.

The problem is that, for instance, if you look at the humanitarian corridors in the suburbs of Damascus in 2018, people who decided not to leave because they were scared were subsequently labeled legitimate targets by the Russian military.

The narrative was that people could leave and those who stayed were "terrorists". So this is of potential concern regarding what we might see in Ukraine going forward.

And of course if we just look at the issue of Mariupol and the attempt to establish humanitarian corridors there, it's proving very difficult. I want to point out one final complication here. When corridors were established in Syria out of these de-escalation zones, there was usually a kind of option given by the Russians.

People could surrender and lay down their arms and stay; or they could leave. Then they would usually leave for Idlib. Now in Mariupol you have the issue that apparently civilians were forced to evacuate to Russia, that evacuation buses were carrying hundreds of civilians from Mariupol to Russia, where some civilians were even apparently forced to give alternative evidence of what really happened in Mariupol.

Regarding the use of chemical weapons, there's a lot of fear that the Russian military might use these at some point. Under which circumstances do you think it might be an option?

Let me perhaps start by saying that I think, generally speaking, a red line over chemical weapons use in an armed conflict has been greatly weakened due to [what happened in] Syria.

Even after Syria declared that it had destroyed its chemical weapons stockpile, we saw repeated use of chemical weapons in that conflict. And Russia essentially has been shielding the Syrian government against attribution and accountability at the OPCW, the Organisation for the Prohibition of Chemical Weapons.

The UN Security Council and Western countries have failed to restore that red line over chemical weapons use.

Then of course there is the question: Would Russia use such a weapon in Ukraine? And the question is not just about whether Russia would or wouldn't fear consequences and attribution.

Things like the Bucha massacre show us that Russia cares relatively little about being blamed by the international community for such atrocities.

The question is still: Would they consider it useful? When is a chemical weapon an effective option in a military conflict?

Now, if you look at the Assad government's use of chemical weapons in Syria, it was usually closely operationally and tactically intertwined with its conventional campaign against the armed opposition, with the purpose being collective punishment in opposition-held areas, alongside sieges and the use of other indiscriminate violence.

I think the implication here for Ukraine is to ask, if we move into a war of attrition — and I guess some analysts would argue that we are already in a war of attrition — in which you need to wear down the civilian population of the other side over time, would you calculate that using chemical weapons might make sense? Especially if you don't consider the costs of doing so to be all that significant.

Let me perhaps just end by saying that even if Russia were not to use chemical weapons in Ukraine, this constant false flag propaganda about the other side staging a chemical weapons attack, is nonetheless useful for the Russian government.

First of all, because it underpins its narrative to its own population at home that the threat of weapons of mass destruction is actually emanating from Ukraine vis-a-vis Russia. So that makes it useful.

Of course, the mere possibility that it might happen creates fear and terror in Ukraine. And then it's also occasionally picked up by conspiracy theorists in Western countries, and it sows doubts as to whether Russia might actually not have a point here or there.

So it's also quite convenient for Russia at relatively little cost, if you think about it.

The interview was conducted by Mikhail Bushuev