Jack Watling, a specialist in land warfare at the Royal United Service Institute (RUSI), a thinktank in London, says India should reassess the resilience of Russian systems such as the S-400 missile defence system, though he does not suggest that India stop purchases of Russian weapons altogether. Mr. Watling is the author of The Arms of the Future: Technology and Close Combat in the Twenty First Century and he works closely with the British military on assessments of the future operating environment. He has also worked with the Ukrainian armed forces and in North Atlantic Treaty Organization (NATO) countries. Excerpts of the interview with minor edits for readability:
RUSI has published a paper (on December 12, 2025) saying, “Russia’s international customers for air defences should reassess the resilience of these systems to attacks, including cyberattacks, technical compromise and disruption of resupply in supply chains”. What specifically does this mean for the S-400 which India has acquired?
If we focus on S-400, the first thing to consider is, what is the defence planning assumption that leads India to acquire this system? Primarily it is about India’s ability to defend itself from China. There is a secondary requirement to protect India from Pakistan, but China is the primary threat. If we look at the Russian defence industry as a whole, at the moment, about 70% of machine tooling is Chinese and (from) Russian defence concerns. Then if we look at the remainder of the machine tools, they are largely European, American or Japanese. Those are the machine tools that perform the most critical functions, let’s say the most precise tools. Many of them were either acquired before the full-scale invasion (of Ukraine in February 2022) or they have been procured through illicit finance. The ones that were acquired before 2022, many of them are reaching the end of their warranty period by 2027 and so in order to maintain them, the Russians have to use subterfuge to acquire more replacement parts and so on.
Now, a huge proportion of those channels for obtaining replacement parts goes through China. To give you another example, the microelectronics that are in S-400 use PBC laminates which are manufactured by an American company called Rogers. The Russians have tested Chinese alternatives in case they can’t get hold of this US materiel, in which case there is a reduction in performance.
Now for Europe, the view is, “Okay, so if we cut that off, there would be a small reduction in performance of S-400, but they would still produce it.” But for India, if the assumption is that India will fight China, and that’s when it needs these systems, then, given that much industrial exposure on the Russian side to China as a critical enabler of all of these production processes, how confident can India be that the Chinese will allow the Russians to resupply them? That is a strategic risk with this system.
So, you’re saying it’s not just the question of China potentially not being willing to allow Russia to resupply, but there’s also a quality issue (with Chinese parts)?
Yes, there is. So, the Russians look at import substitution options to protect their supply chains. So, their technicians take the current component and they take alternative components that they think could perform a similar task, usually Chinese ones. We have the laboratory tests that the Russians have performed. And what they demonstrate is very clear, which is that in some cases, there is no Chinese substitute, so there isn’t an alternative component they can source…. And in some cases, the system will still function, but it will just it will perform less capably.
Are these your arguments against India acquiring the S-500 system? Because there was some buzz about that in the Indian press.
My understanding is the Russians aren’t prepared to sell S-500 to India at this stage. But there are other issues there. So, for example, the critical radars in S-500 all rely on beryllium oxide ceramics, which are produced by one company called Kaz Ceramics, based in Kazakhstan. If anything happens to that factory, then Russia’s ability to produce new radar for the system will be critically compromised, which means that you are putting your ballistic missile defence capability in quite a vulnerable basket, if you were to rely on S-500 as the system to protect you. In many cases, I don’t think this is necessarily an argument for why India should scrap all Russian equipment. It’s not about that, because India has a lot of Russian equipment. It has people who know how to use it and maintain it. It’s invested a lot in these capabilities. And in some instances, there isn’t an alternative on offer.
Such as (for) the S-400…
Yes …(India hasn’t) been offered Patriot (the U.S. manufactured Patriot surface-to-air missile defence system), for example. You might run into all sorts of issues obtaining Patriot reloads, right? So there are issues there.
The terms on which India makes itself dependent in this way need to be looked at very carefully. So, India probably wants to produce domestically and have technology transfer; it probably wants to work out how it can assure the supply chains to be able to produce it. If you look at P-800, which is the Bastion P, (it is a) missile defence system for coastal defence that India acquired from the Russians initially but then did co-development to produce an Indian coastal defence missile that can fire from the Russian system. I would be looking to work out how India can do that. This has previously been framed as a ‘Make in India’ (initiative’) for the sake of your (India’s) prosperity and industrial development. Fine, but there’s actually a fundamental security requirement to not be exposed to what is quite a vulnerable supply chain.
There’s also the question of whether there is a like-for-like substitute for the S-400. It’s not just a question of the Patriot not being on offer…
So, it depends what you shoot them at, right? So in the four-day war (i.e., the May 7-10 India-Pakistan conflict/ ‘Operation Sindoor’), India shot a lot of S-400 interceptors at drones, which is a very poor weapons match. You’re firing a very expensive, scarce missile at a very cheap object. Everyone’s made this mistake. The Israelis used to shoot Patriot missiles at quadcopters (a UAV). But what that speaks to is the need to have a layered air defence system with appropriate layers for the threats. And there are substitutes for S-400 for some of those layers. There are some specific areas where the S-400 is distinctly valuable for India, tactical ballistic missile defeat, for example (or) certain types of aircraft flying high altitude profiles. But if you can narrow your dependency on S-400 for those particular targets where only S-400 is the answer, then you’re going to use far fewer missiles. So, you reduce your own vulnerability. If you have to use S-400 for everything, you’re going to run out of missiles, and the Russians aren’t going to be able to resupply you.
Around the recent visit of Russian President Vladimir Putin to India, there was talk of Russia selling the Sukhoi 57 (Su-57) and Sukhoi 75 (Su-75) to India. The West and NATO countries, in general, will have a commercial and strategic, political, interest in India not acquiring these aircraft from Russia. But purely from a capability and technical angle, you believe that this is not a good option for India. Why?
On Su-57 and 35 and Su-34… firstly, Russian aircraft production is also exposed quite significantly. We published a report in November which outlines the supply chain vulnerabilities of Sukhoi production. It’s also significant.
More importantly for India, however, the biggest problem the Indian Air Force has is aircraft availability and pilot training hours, because you have seven different fleets which is unimaginably inefficient, some of them very, very old. And if India wants to. maximize the effectiveness of its air force, it needs to consolidate the number of fleets that it operates to fewer fleets.
If you put Su-57 against Rafale, they’re comparably capable. It will come down to what munitions they have, the training of the pilots, that kind of thing, to determine which aircraft is more capable. But if you have Rafale already, the idea of also buying Su-57 is you’ll end up with two fleets that are smaller as a result, and the Air Force will be less capable. From the Russian point of view, they want someone to fund the program, because otherwise they can’t fund it. So they’re very interested in you (India) buying them.
On the topic of Vladimir Putin’s visit to India…
I think there was a desire on the Russian side to show that Russia is not isolated, it still has allies and friends, and this is a message that they’ve always wanted to push. India has been a very important part of that. The Russians have issues with selling oil and the terms under which oil is sold.
Therefore, it’s an important relationship for the Russians, because it accounts for a lot of revenue. And so the Russian intent was clear. And then the Russians want to secure long term sales for their defence industry, because they have put their defence companies into eight to 10 years of debt and forced them to invest their own money into expanding production capacity, when they can only make 2.8% profit selling to the Russian government during the war. So, they need customers after the war. Otherwise, a lot of these businesses are going to collapse and the Russians suffer an economic shock. So, the Russians are trying to lay this foundation to secure their economy and their military industrial base.
On the Indian side, I think the government will have wanted to message the Americans and others, that, ‘we have these relationships’, that they’re important and that ‘we have options’ and that ‘you can’t just coerce us’. But at the same time, there wasn’t a big public announcement about weapons and so on. I think there probably were more substantive conversations held in private but not announced. And I suspect that is because officials didn’t want to antagonize the U.S.
If the Russia-Ukraine war were to end would end soon, say within the next three to six months…
I think there’s a possibility the war will end in the second half of 2026.
Okay, so within the next year. What does this mean in terms of Russia maintaining state of the art capabilities of its defence systems and weapons where those currently exist, and developing those in areas where they do not exist? Because your papesr has offered some praise for some of Russia’s systems.
So, the Russians have become much more capable over the course of the war because they have had real world engagements and, therefore, they have gathered real world data and have used that to refine the performance of their air defences, their electronic warfare, their aircraft, their communications, …drones, in particular. In some areas, like UAVs (unmanned aerial vehicles), they’ve created new capabilities that they didn’t have before.
At the same time, their adversaries have gathered a huge amount of data on exactly how all these weapon systems work…The Chinese have been doing the same to those Russian weapon systems, and what we have seen is that, in certain circumstances, the Ukrainians have used that knowledge to compromise these systems very effectively, so that they don’t perform as they should.
So we have two stories. One is the baseline performance of the systems has improved. When the Russians stop getting real world data, that will probably slow down, because suddenly they’re using simulated targets again and so on. But the number of ways in which you can bypass that baseline performance has also increased, because as the adversary understands the quirks of how the system works, they can exploit them.
You specifically mentioned that China will have leverage on Russia in terms of what it can do with its systems and so forth, as a supplier of parts, and also the (issue around) quality of the parts in Russian systems. What are the other direct implications for India at the capability and technical level from Russia-China cooperation?
…I think the challenge for India is that its primary defence partner Russia is much less able and is much less interested, at this point, in providing a firewall between its technical cooperations with India and its technical cooperation with China, which poses challenges, because the risk is that the Chinese can compromise Indian defence capability prior to a conflict.
Earlier, you expressed some confidence that the Russia-Ukraine conflict might end in the second half of 2026…
I said it’s possible. So, the Russians currently are saying they think constructive negotiations can start in March or April. At the moment they are setting up conditions where Ukraine is having to negotiate furiously with the US. And then every time something is kind of taken to the Russians at a working level, they’re like, “Hmm…it’s interesting. We’ll have to discuss a few things.” And at Putin’s level, its, “Nah (no).”
Why? Because the Russians perceive themselves to be gaining more and more leverage through the trajectory of events on the battlefield. So, the Russians think that they can get to the beginning of summer next year and they will have acquired much more leverage to impose far harsher terms in eventual talks. They want to use these talks to stop the US providing military technical assistance to the Ukrainians, and that again, increases their battlefield advantage. So, the Russian plan is to settle then.
If we go the other way and we say, when, when might the Russians start feeling pain? Well, if there’s systematic action against the shadow fleet; if India stops buying their oil, if – you can put the ‘ifs’ in – if there’s enough leverage on the Russians and they haven’t achieved their accelerated military gains in the first half of next year. Then the Russians are going to have to be mobilizing reservists, rather than having volunteers, in order to generate the replacements…the economy probably looks in recession. And so, the Russians might be prepared to take an offer which walks back some of their more maximalist claims.
It’s not a guaranteed thing. I think the U.S. administration’s desire to get this done by Christmas or done by the end of ( U.S. President Donald) Trump’s first year in office – these are arbitrary timelines.
You had mentioned earlier that you don’t necessarily think that India should stop the purchase of Russian equipment altogether…
I think India has a huge scale of demand, and that can’t necessarily be serviced elsewhere. There is also a sunk cost. India has this equipment, and it knows how to operate it, so it’s not that India should divest of all its Russian defence relationships, but I think India needs to make sure that it fully understands both, not just where something comes from, but then the supply chain that sits behind that. How resilient is it? How exposed is it?
Because when you buy defence materiel, and this is what Europe has found, very painfully, during the full-scale invasion of Ukraine: if you don’t know what the second and third tier of the supply chain is, you get into a conflict, you start spending money, and the company that you’re giving money to can’t actually get a product back to you. That is how you end up having your defence assumptions undermined in terms of your capacity to sustain a conflict.
