Russia has stuck by the Syrian regime leader through thick and thin – but the alliance is under more pressure than ever.
Pressure is building on Russian President Vladimir Putin to sever a troubled alliance with Bashar al Assad after a deadly sarin gas attack killed 87 people, including 31 children. The US responded with a missile strike on a regime military outpost.
Foreign ministers from seven of the world's leading economies and Gulf states also endorsed the call for Russia to abandon Assad. The G7 meeting in Italy said Syria's civil war, now in its seventh year, can only end if Assad is out of the picture.
US Secretary of State Rex Tillerson was expected to persuade his Russian counterpart Sergei Lavrov at their first meeting in Moscow.
Russia has long stood by the Syrian regime militarily and politically – from its full-scale intervention in late 2015 that turned the tide of the war in favour of Assad's forces, to repeatedly vetoing punitive resolutions on Syria in the UN Security Council.
But the uproar over the chemical weapons attack in last week could turn Russia's alliance with Assad into a liability.
TRT World spoke to two experts on Russian and Syrian affairs about the likelihood of Putin reviewing its relationship with Assad.
How does Russia benefit from its relationship with Syria and what are the risks?
Alexei Khlebnikov, Russian International Council for Foreign Affairs: Syria is important to Russia's ability to project power into the region. All other regional powers have their assets there, so it's important for Russia to have theirs, too.
Russia has had a long-standing military presence that goes back to the Soviet era.
Syria is Russia's only outpost in the Middle East. Since fall of 2015 it is home to Hmeimeem Air Base. Also, Russia decided to upgrade its naval facility in Tartous to a naval base, which will be able to host big military vessels like aircraft carrier and nuclear submarines.
Aymenn al Tamimi, Middle East Forum: Besides obviously its military bases, I think it's the way Russia has been able to present itself as being this major power in world affairs, and presenting the way that they've managed to best the US and its allies on the whole Syria thing.
Then of course there's arms sales, and all of the debt to Russia that Syria is now in.
Russia is of course facing new sanctions, but I'm not sure that will severely impact Russia's ability economically to conduct this war. It's not been too much of a problem for them at all, in fact you could say their efforts and benefits have been remarkably efficient.
Could Russia realistically abandon Assad?
Aymenn al Tamimi: I don't think it's likely, actually. I think Russia's leverage over the regime is overstated, particularly when it comes to Assad's position in power. There's been talk in the past about Russia being amenable over transition, and not necessarily being bound to Assad's staying in place, but I think this overestimates the amount of leverage they have over him.
It might be the case that behind closed doors that Russia has been trying to make proposals where Assad would step down. The problem is that the regime doesn't go with that. So whether Russia wants it or not, they're made to go along with the Syrian state.
The regime uses its relative military weakness to convince the Russians that they have to accept that Assad stays in place and that there isn't an alternative, otherwise the Syrian state will collapse.
For example just in the past year or so, looking at things like the retaking of east Aleppo, there wasn't a grand Russian plan from the beginning, it seemed like the regime dragged Russia into it, so they were compelled to accept the idea that they just had to take it by military means.
When it comes to the question of Assad's position and whether he gets to stay in power, the regime presents him as an absolutely indispensable figurehead, and somehow they're able to drag Russia to go along with that, other than Russia being able to pressure the regime to make Assad step down.
Alexei Khlebnikov: We should remember that Russia doesn't ally with Assad personally – it supports the Syrian state institutions, to keep the country from slipping into chaos.
As long as Russia's interests in Syria are kept, it doesn't matter to them who is in power.
I don't think that Russia will agree to something that leaves Assad out of the transition process, although ultimately it is up to the Syrians to decide what to do with their own country. But for now, Russia will do everything it can to hold onto its previous stand – to not allow the regime change happen.
And where does this leave Syria and Russia's mutual ally, Iran?
Alexei Khlebnikov: What makes Russia-Iran relations quite tricky is that Iran is connected to Assad regime more than Russia and it invested heavily in it. It's important to Tehran to keep Assad family in power, but for Russia, Assad is not a person for whom it will go all-in. Moscow's primary goal is to safe Syrian state institutions, not the personal rule of Assad.
Aymenn al Tamimi: Iran is definitely committed to Assad. It's position is basically identical to that of the regime, that Assad is indispensable, whereas the Russians don't really believe that but they're made to go along with it. You could say that Iran is more closely aligned with the regime than the Russians are, but in practice, whether that could ever be used in negotiations is very questionable.
Reporting by Shawn Carrié