The interplay between deterrence and defence


Deterrence is about the adversary's impression of your capabilities compared to his perception of his capabilities. 

Meanwhile, defence is about your actual capabilities compared to your adversary's actual capabilities.

Errors of judgment aside, the difference is mostly the difference between your communicated capabilities and your real capabilities (communicated + hidden).

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Now imagine you're a political leader and have to issue a task to the armed forces. Will you tell them to focus on deterrence? Will you task them with deterrence AND defence?

To focus on deterrence requires to communicate your capabilities well, secrecy would serve only to protect your capabilities (code secrecy and such). You can jam the adversary's battlefield radios? Let him know! You can stop his anti-tank missiles? Let him know! This may be a quite expensive path, as it provokes an intense offence-defence spiral as your adversary will strive to defeat your capabilities once he understands them.

To order both attention on deterrence and defence makes things difficult and it's indeed not an accurate guidance for the armed services. As was shown above, to bolster defence may deteriorate deterrence, and vice versa. The armed services can only fully meet this order with a budget much superior to the adversary's.

To order a focus on defence leads down the path of secrecy. Your armed services would build up an arsenal of mean surprises, but that could provoke a fatal underestimation of their capabilities by your adversary - and thus to a war that's still disastrous to health, prosperity and even culture of your population.

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What's the optimum? I consider just about every war to be a very bad event (exception; intervention against beyond reasonable doubt ongoing genocide), so I would want to avoid it. This requires effective deterrence. But the deterrence focus approach described above is excessively expensive in peacetime, and might actually fail to deter if you cannot afford it.

A smarter way might be to limit the communication of capabilities to just the needed amount for short-term deterrence, and convincingly communicate additional capabilities once there's a heightened risk of war (remember, the task is deterrence) or when you suddenly become convinced of additional adversary capabilities (which would call for more communicated capability of your own to deter).

The smartest way is to turn your adversary away from hostility towards a stable peaceful co-existence in which both model you and your model adversary can live with each other and without wasting many resources on the capability to harm each other. Deterrence should be considered to be the price to pay to buy the time for developing such stable peaceful relations.

P.S.: This was written from the perspective of a power with superior resources that wants to avoid wasting resources. A power with somewhat inferior resources might try to deter by fostering uncertainty, promoting rumours and advantageous stereotypes instead of communicating real capabilities.


  1. Have you read "Defensive Verteidigung" by Horst Afheldt. I came across it almost 10 years ago and really liked it. It argues for a German army purely built for defence and incapable of offence to diffuse cold war tensions. Today i see many of the conclusions as quite naive, but his focus on rocket artillery and AT mines is very interesting. I can really recommend it: www.buchfreund.de/de/d/e/9783499153457/defensive-verteidigung?bookId=75904912

    1. There were multiple alternaitve army design and doctrine concepts during te Cold War. The only one that was kinda realised was Spanocchis Raumverteidigung in Austria.

      The alternative concepts for Germany failed possibly due to path dependency: West Germany had decided in the early 50's that it wouldn't just become a provider of auxiliary infantry to the Western allies. It wanted a proper army. The labour shortage did set in by the late 50's due to economic growth, so infantry-centric doctrines that looked personnel-intensive were considered unsuitable. The military was supposed to make do with no more young men than it already had.
      The alternative doctrines were mostly very infantry-heavy.

      In the end, NATO badly lacked infantry and scouting/observation forces in Central Europe becuase of the West German policies. Uhle-Wettler decried this repeatedly in publications.

      The Warsaw Pact was rather short on infantry as well unless you consider the low quality reserves and "Arbeiterkampfgruppen".

    2. "In the end, NATO badly lacked infantry and scouting/observation forces in Central Europe becuase of the West German policies."

      No dispute. However, what would have been the alternative? More infantry with less Panzer and Panzergrenadiere? Or was the actual structure the lesser of two evils?

    3. I suppose a Raumverteidigung-style militia with reservists would have been a better allocation of funds than the second-rate previous generation equipment territorial army (reserve) brigades and the Transalls. There was also never a good reason for paras and mountain infantry.

      So basically I'd have preferred (ex post) ana ctive field army based on one standard mechanised brigade type, a Raumverteidigung militia for presence everywhere (gaps filled with border guard units assuming the same role), a marginal navy (though some Exocets on trucks and enough Seehund minebreaker RPVs controlled from land) and a F-5E/F/G based air force (all 'Schlachtflieger' air force).

  2. Poland allegedly plans to double its force to 300k, which, given economics, should be more infantry centric than Germany or France. This decision is made according to a claim that in war games, Poland can't defend its capital and has to surrender to Russian pressure within days.
    A problem with this build-up in Poland is that the Polish army is mostly on the German border, which makes little sense if they plan to defend Warsaw against a Russian attack. Another problem is that they opted for such a large number to defend a country the size of Germany. If Germany and France follow this Polish lead, at least Germany runs into the upper limit in the 2+4 treaty.
    While this Polish build up is claimed to be for defence, because the current force is consider insufficient to deter the Russians, I wonder about a third option, attack or at least the threat thereof. Poland and Russia could potentially split up Ukraine, with each side invading to defend their friendlies. This double defence could end up in mutual attacks on each other to capture a greater share of the country both sides would claim to be an ally they support in defence. In case of such a misuse of defence, miscommunication and misjudgement might be goals to lower the perceived deterrence value and bring about a confrontation to resolve a powerplay.

    1. I wrote about this a bit.

      That 30k national guard thing that was being talked about years ago looked too much like a political stunt to be taken seriously. Cheap reserve infantry without proper doctrine, training, junior leadership development and quality key hardware would be worth little It would be akin to the mobilised reserves of Georgia, which did close to nothing in 2008.

      I'm not aware of arms limits in the 2+4 treaty (though I sure haven't read it in decades). Maybe you meant CFE.

      Regarding interventions in Ukraine; I suppose we should build up deterrence for Ukraine that falls short of hot war and is laid out in detail in advance to avoid misunderstandings.
      A declared drôle de guerre might fit. Total communications and economic blockade plus naval blockade, if need be for decades. Russia would rot and be offered the choice to become a Chinese puppet or let the Ukrainians go.

      But I don't think at all that Russia can bite off more from the Ukraine than it already had (Donezk included). The Ukrainians are moving away from everything Russian at full speed.

    2. Article 3 section 2 of the 2+4 treaty limits the size of the German military to 345k. So if Poland starts a new round of arming up in Europe we live in interesting times.

      Did you just write why a navy might be sometimes useful when you suggested a naval blockade of Russia? I don't agree with you, but still an impressive train of thought from you.

      The Russian and the Ukrainian POV differ. Russia sees Ukraine as part of the " Russki Mir", which includes more than nationhood, being more akin to the Chinese view of themselves as one civilization that owns several countries. Many Ukrainians disagree, because they want to be more like Poland with whom they had been in a commonwealth. It will be decisive if Germany backs this interpretation. It could lead to a territorial expansion of territory under EU law. Germany thus increases its zone of influence at the expense of Russia, although Poland is likely to be the main protagonist and benefactor. So we have an interesting case, where Germany might be forced to defend an aggressive ally and deter a possible counterattack on Poland.

    3. 370k, 345k is the figure for air force + army.
      This is not really an issue. There's a gazillion ways to cheat around it if necessary. We could run mandatory one-year service in recreated paramilitary border guards, for example.
      Many military jobs have already been outsourced. Aircraft mechanics, car mechanics, supply, truck drivers, administration - we could easily outsource half of the jobs to government-owned companies who only employ reservists and would be turned into military units the moment of mobilisation.
      The navy could maintain two marines brigades et cetera.

      A 370k limit allows a mobilised strength of a million ready personnel and it would merely be a violation of the treaty in spirit, but the Russians have no moral standing to complain after their violation of Ukraine's sovereignty after having guaranteed the same.

      It's like the CFE treaty limiting heavy mortar quantities and suddenly 98 mm becomes a mortar calibre. Such treaties only matter as long the the underlying intent persists on both sides.

      I can assure you that hardly anyone in Germany thinks about the Ukraine. The German government may play some games for politicians' entertainment, but it won't do anything big about the Ukraine.
      The biggest thing that I consider realistic is a delivery of old weapons and munitions similar to how the YPG received shipments, but I doubt we have many useful Milan missiles and launch posts left.

    4. You wrote a piece on Baltic defence some time ago. Would you do one for Ukraine as well? The idea of the Russki Mir is influential in Russia, and Ukraine might be invaded in the next years as a breakaway from the community, which also includes Russia, Belarus and Kazakhstan.

      I doubt sanctions by Western nations will have the desired effect on Russia when the biggest trading partner of most countries in the world is China and Russia earns most of her income thru resource extraction. So the acceptance or toleration of an invasion and occupation of Ukraine could also affect other groupings who regard themselves less along the lines of nationhood and more as civilizations with with one to several countries. This would be as a group the PR China, Taiwan, and Singapore, maybe Nepal. Others in the long term could be Albania and Kosovo, India and her neighbours, including Nepal, and Iran for the Persian civilization that includes Azerbaijan, Afghanistan and Tajikistan.

    5. Germany has bad experiences with pan-Slavism. It's one of the First World War causes (the other being Austrian aggressiveness).

      The Ukraine security situation is balancing act, not my forte. The relative lack of diplomatic efforts for peaceful conflict resolution indicates that the great powers think that the interests of Ukraine and Russia are too incompatible for a short or medium term conflict resolution. It's probably going to fester on for generations like the Kashmir Conflict.

    6. Thank you.
      The Russki Mir concept is more limited than Pan-Slavism and not limited to Slavs. It excludes the Poles and doesn't consider parts of Germany as ancient Slavic territory to claim. "Mir" means community, such as a village community or the space station.
      So it can be assumed that this situation will fester and at some point all such festering problems all over the world can blow up, probably simultaneously.

  3. I wonder if such defencive concepts which failed because of their infantry heavy core could be implemented today in the form of robotic warfare in which robots and automatic weapons would replace the infantry needed. Robots in the widest sense, from ied to mines to ugcv, to ucavs. This would free humans from the military so that they can work and produce wealth etc and the industry delivers the needed quantitiy for this concept in form of robots.