I would generally be extremely skeptical of the idea of any current terrestrial power having developed fusion capability. This is a technology which is definitely not just around the corner, it's generations away from being a practical reality. I would personally be surprised if commercial fusion is a thing in my lifetime (I'm 32), though obviously humanity has a habit of surprising people with the speed of its ingenuity so who knows.
Is it possible that some other country has discovered some elaborate mechanism that everybody else is totally unaware of which cracks the ability to create fusion reactions? Sure, it can't be ruled out 100% but it would be like finding the philosopher's stone or something. Very unlikely. And there's all kinds of evidence that suggests this isn't the case. Firstly, you can't hide the kind of high-energy physics facilities you need to develop something like this. It's like trying to hide a nuclear programme. The world knew North Korea was developing nuclear weapons way before they told us.
All major governments are pumping billions into fusion technology and so far the best results we have are from programmes like the NIF where they have achieved Q > 1.5. Meaning that the reaction achieved 50% more heat than it used. Which sounds great but the hard part is sustaining that reaction and then extracting that energy gain. This requires building enormous magnets to generate and sustain superhot plasma and an entire power plant infrastructure which is very energy intensive. Some estimates suggest that the Q-value needs to be closer to 100 to be widely commercially viable (though it might be possible to operate at lower Q-values with new engineering breakthroughs). This is after 70+ years of development knowing fusion is a thing.
As a result, the best we've ever done in the many projects across the globe is to obtain about 1% of the energy out of a fusion reactor that we would need to generate power commercially. That's a slight oversimplification because the way these things scale is not strictly linear and there's all kinds of considerations on technical challenges with sustaining the kind of heat we're talking about.
The biggest indicator that nobody has done it already is the existence of ITER. This is the biggest human collaboration project since the ISS. This reactor will cost over 20Bn and is being funded by the EU, China, Russia, the US, Korea, Japan, India, UK and Switzerland. When built it will go online in 2025 but it won't start high-power interactions until 2035 - over 10 years away. It aims to achieve momentary Q = 10 and sustain Q = 4 for 8 minutes. This means at best by 2035, the most ambitious global fusion project will be somewhere between 10-25% of the way to sustainable fusion. And sustainable fusion is not the same as commercial viability. We are - to be frank without being overly negative - still absolutely miles away.
And we're talking here about taking the above concept and shrinking it down to the size of something that can fit in an aircraft. For a country like Russia to have done this it would be a bit like they'd invented the smartphone before even inventing telegrams. Just not really feasible.
Disclaimer: I speak as somebody with a physics degree who understands the basic concepts at play here, but I am absolutely not a fusion engineer and I'd advise digging deeper to gain your own understanding.
Well I think you’re much better qualified than I am to be right on this or any other specific scientific topic.
However, despite the widely held supposition that scientific knowledge and technical expertise develop in a roughly linear fashion, it’s no secret that the major changes actually come in leaps and bounds without following any regular or incremental pattern, and history proves this to all who care to look.
One amusing example of this was witnessed by millions of us watching the fraud Uri Gellar supposedly bending spoons on TV whilst surrounded by and closely observed by dumbfounded western scientists who were totally baffled by his seemingly unique and unworldly abilities.
The fact of the matter was that, unbeknown to them, he was simply employing cutlery made from metals with properties (that were well developed in the USSR but beyond imagination in the west) whereby combinations of metal alloys and revolutionary annealing techniques allowed the production of metals that changed shape in a predictable fashion when subject to small temperature changes.
Thus, the heat produced by the friction of rubbing a spoon handle with his thumb could induce that spoon to quite quickly revert to a predetermined twisted state.
What he was doing was employing science that was such a step change from what was known at the time that western scientists couldn’t even conceive of the possibility of what he was demonstrating right in front of them.
The world we live in is shaped by out of synch scientific development. In our world of greed, conquest & capitalism it allowed the use of modern weapons against longer existing and more culturally developed societies, as can be seen in the genocides committed against the North and South American native peoples the native peoples of Australia, Africa etc.
Many of the societies almost completely wiped out by the guns and bullets that we developed in only a handful of decades had histories going back so far that we were cave dwellers at a time when they already had rich histories.
And developing and proving a science doesn’t necessarily mean that a step change to use that knowledge in it’s most dramatic fashion happens.
The Chinese had ‘gunpowder‘ and had been using metal lamination to produce blades that were light and flexible without being brittle, while we were still fighting with sticks, but they didn’t take the next small step that could have led quickly to the production of the guns that we used to subjugate the rest of the planet.
I suppose that the point of what I’m saying is that step changes in scientific knowledge are more the norm than the exception.
What seems impossible today can be in common use in very little time and I say this as a bloke who grew up with black & white tv on 2 channels only, and a home telephone on a party line that worked down a string of copper wrapped in waxed cotton, and who’s now sitting in front of an iPad sending information via Wi-Fi and then down a fibre, through a server on the far side of the planet to appear in print on this here forum.
What I’m doing right now was totally impossible to the degree it was inconceivable to all except except some theoretical thinkers until not long ago at all. Indeed, the clunky iPad type devices used in early Star Trek were readily accepted by the viewers as being something that might happen (perhaps) in several hundred years time but it’s with us today.
I await developments with keen anticipation. Y’never know eh? ;-)