With today's shooting down of a Russian SU24 by Turkey, the war in Syria just took a new twist - and one that sends a powerful message to the UK as it contemplates joining in bombing raids on Islamic State militants.
And for those who are hard of hearing, that message is: 'keep well out!'
Up until now, the war in Syria has looked complicated. On the one side the Syrian state led by President Bashar Assad, supported by its long term ally Russia, Iran and Iraq - 'Them'.
On another side, Islamic State (IS) and allied terrorist groups.
And finally the US, Turkey, Saudi Arabia, Qatar, France and Israel as a silent partner, allied with 'moderate rebels' in Syria whom they equip and finance. Very possibly to be joined by the UK, at least if David Cameron gets his way. Collectively, 'Us'.
Of course there have been well-supported allegations that those last two sides are actually one and the same. Much as the US supported Islamic terrorists in Afghanistan to attack Russia in the 1980s (and has been suffering the blowback ever since), the theory goes, so it is now supporting IS as a proxy force against Syria to advance its geopolitical goals.
But now it really looks like it's all true. NATO member Turkey's shooting down of a Russian SU24 that was, so the Russians insist, a full kilometre inside Turkish air space, has been described by Vladimir Putin as "a stab in back" by "terrorist accomplices".
What is certainly beyond doubt is the many credible accusations that Turkey has long been allied with IS as a proxy force in its own internal and external war against the Kurds - a downtrodden and disenfranchised people in Eastern Turkey, but increasingly empowered in their autonomous regions of Iraq and Syria, where they have been highly effective in the sharp end of the fight against IS.
So what about all that talk from the US, the UK and other governments that IS represents an existential threat that must be destroyed? A rhetoric that has, of course, grown all the stronger since the horrific attacks in Paris of 13th November?
I am reminded of the fabled words of St Augustine: 'Lord, grant me chastity. But not yet.' Yes, IS is an evil, even genocidal organisiation that represents a long term threat to civilisation everywhere. But for now, it's serving Us far too well. The time will come to turn against IS - once Assad is finally defeated.
It was all going so well! Until Russia stepped in
And it has to said, things were all going to plan. Syrian government forces were outnumbered and outgunned by IS which had been gaining ground across the country, seizing key oilfields and associated infrastructure (earning it a reputed $1.5 million a day in oil sales), and armed by sophisticated mainly US weaponry supplied to 'moderate' rebels who promptly joined up with IS.
But then this summer Russia moved into the Latakia air base in western Syria, beefed up its defences, and moved in its military aircraft. Bombing of IS and other rebel positions began in late September and have continued ever since with increasing ferocity and effectiveness.
Suddenly - after IS had somehow survived and flourished after a full year of US bombing raids - IS was suffering serious damage from the air, while re-emboldened Syrian ground forces, working under Russian air support, began to regain territory and key strategic objectives such as the Kweyris military base east of Aleppo which may now form a second base for Russian aircraft.
And for all Our complaints by that Russia was mainly attacking 'moderate' rebel forces supported by Us, rather than IS, IS was upset enough - or so it seems - to place a bomb in a Russian tourist aircraft returing from Sharm-el-Sheikh to St Petersburg on 31st October and kill all 224 occupants above Egypt's Sinai desert.
The US was forced to step up to the mark and show that it really was taking the IS threat seriously. For the first time, for example, US aircraft attacked convoys of oil tankers travelling to the Turkish border last week, destroying 116 of them and another 283 over the weekend.
This certainly adds up to a credible military action - but gives rise to the question - why did it take them so long?
Into the cauldron of fire?
It is into this highly unstable situation that David Cameron wants to commit UK armed forces and get bombing. Last time he sought Parliamentary approval for bombing in Syria, remember, he lost the vote on 30th August 2013. And that time, it was President Assad's forces he wanted to bomb.
Now, barely two years after that well-earned Parliamentary disaster, he's even keener to get bombing. Only this time, it's the other side he's after destroying - IS. But is it really? Or is the truth that it's the same old game plan all along?
It increasingly looks as if the sudden enthusiasm for bombing IS in Syria has more to do with claiming territory in the west of a broken up and Balkanised Syria for Our so-called 'moderate' rebels, and hold Assad and his Russian allies at bay. And that goes not just for the US but for the UK as well.
So what's going on? One often ignored dimension is the 'battle of two pipelines' to carry natural gas from either Qatar or Iran across Syria to European markets. The Qatari pipeline would transect Saudi Arabia, Jordan, Syria and Turkey on its way to Europe. The Iranian pipeline would go across Iraq and Syria before dipping undersea across the Mediterannean to Greece.
As reported on ZeroHedge, "Knowing Syria was a critical piece in its energy strategy, Turkey attempted to persuade Syrian President Bashar Assad to reform this Iranian pipeline and to work with the proposed Qatar-Turkey pipeline, which would ultimately satisfy Turkey and the Gulf Arab nations' quest for dominance over gas supplies.
"But after Assad refused Turkey's proposal, Turkey and its allies became the major architects of Syria's 'civil war' ... now we're seeing what happens when you're a Mid-East strongman and you decide not to support something the US and Saudi Arabia want to get done."
And it so happens that with a good chunk of western Syria under Our belts, Qatar could have its pipeline up through Saudi Arabia, Jordan, Syria and Turkey after all - while also blocking Iran's pipeline route to the Med.
Is this really where we want to be sending 'our boys'
Now all of this is a dangerous game for our airmen and aircraft to be getting involved in. With increasing rancour between Us and Them likely to develop, and hardening competition for land and key pipeline routes across Syria, Turkey's downing of the Russian SU24 may be only the first of a number of miltary encounters that could ultimately lead to direct confrontation between the US and Russia.
If so, many might feel that his would be something the UK would be best off taking no part in. Despite Cameron's desire to please the US, Saudi Arabia, Qatar, Turkey and other allies, it's hard to see anything at stake here that could really be called a 'national interest'.
The Labour leader Jeremy Corbyn has rightly sounded a cautious note over the UK joining in air strikes on Syria, calling for a "political solution" rather than a military one. He could also point out that there are other far more effective ways in which the UK government could make life difficult for IS if that really is its objective.
For example, it could investigate the means by which funds are transferred to IS both within the UK and in other countries that have dealings with the UK and our financial institutions, and act to cut off the flow of funds. It cold also do more to ensure that weapons sold to friendly states like Saudi Arabia do not end up in IS hands.
And as former Lib-Dem leader Paddy Ashdown pointed out on the BBC Today Programme this morning, the UK has in fact been singularly reluctant to do either:
"The failure to put pressure on the Gulf states - and especially Saudi and Qatar - first of all to stop funding the Salafists and the Wahhabists, secondly to play a large part in this campaign, and other actions where the Government has refused to have a proper inquiry into the funding of jihadism in Britain, leads me to worry about the closeness between the Conservative Party and rich Arab Gulf individuals.
"Talking about Saudi Arabia and Qatar in particular. I'm not saying their governments have been doing it but their rich businessmen have, and in states like Saudi Arabia you'd imagine the government could stop it."
Stop and think ... are we even on the right side of this war?
And if anyone should be out there bombing IS, he added, it is those same countries that have been funding it: "The one thing the Gulf States haven't been doing is playing a part in the military coalition which they are committed to. The last Saudi plane seen flying as part of the coalition over Syria was three months ago, the last Qatari plane was nearly a year ago."
There is indeed a problem that no amount of bombing will solve. And that is the other key members of very military coalition that the UK wants to join in bombing IS in Syria are entirely unwilling to do any such thing themselves, indeed they appear to be closely allied to IS both in their actions (and lack of them) and their geopolitical motivations.
So if there's any side of the war we should be joining, it's not with Us, it's with Them. How about a request from President Assad to Prime Minister Cameron for fraternal military assistance in wiping out IS from his national territory? Because there is one thing for sure here: They really do want to annihilate IS completely and utterly.
And who knows, that might even be an idea that Jeremy Corbyn could agree to.