Editor’s Note: Glen Grant is a retired British Army officer and defense expert with Kyiv-based think tank Ukrainian Institute of the Future.
The Suwalki gap – the European Union land that cuts through Russia where Lithuania and Poland border – is often talked about as a great NATO vulnerability for supplying the Baltic States overland in the event of a Russian invasion.
Former U.S. Army Commander Europe Ben Hodges told me I should think of it less as a gap and more as a corridor through which we must pass. I visited it last week and certainly “gap” does not do it justice. It is a serious operational challenge for any commander both attacking or defending.
The opposing borders between Kaliningrad (Russia) and Belarus are just 90 kilometers apart but the possible approaches cover more than 20,000 square kilometers of complex terrain.
There is a lot to be learned for NATO armies by studying this problem more seriously. Any defense should draw on the best lessons of the NATO cold war preparations and some of the latest lessons from fighting in Ukraine. Defending to win and not just deterring would demand some changes to how we train and likely also changes within organizational structures.
This issue is topical for the U.S. as it is unlikely that the few Lithuanian forces or even many Polish forces could all be committed to this area alone. The enhanced NATO forces for the Baltic states, like the German-led reinforcing battlegroup embedded in the Lithuanian Iron Wolf Brigade, are powerful additions but they could be overwhelmed by the sheer scale and complexity of the ground to be fought over.
Not to mention the fact that these troops rotate so regularly that no matter how professional they are, there is never enough time to learn the ground properly. This means that in the event of an attack the U.S. brigade in Poland would almost certainly be needed to join the fray to hold the ring.
Polish and US troops take part in the so-called Defender-Europe 20 joint military exercise at Drawsko Pomorskie training grounds in Poland on August 11, 2020. (AFP)
The gap can be divided into three separate routes from Russia or Belarus for any attack.
The southern route through Poland, south of the town of Suwalki is about 150 kilometers from the Russian border to the Belarus border. The region is largely agricultural and flat but with many large lakes and fragmented by both small and large forests. These forests are normally dense and marshy and are virtually impassable for armor off the few logging tracks and narrow dirt country roads.
The agricultural land here was never Sovietized like Lithuania so there are smaller fields with occasional surrounding hedgerows and wood-lines. But there are also many ditches, streams, and rivers draining into the lakes or Baltic Sea making it difficult to walk through. It is a defender’s dream as movement is frequently channeled narrowly along the roads or across open fields by the lakes and forests. But the problem is that the battlespace is at least 5,000 square kilometers.
This area also contains in its center the critical road junction town of Augustow. This is where the main route coming north from Warsaw splits into the two serious supply roads for the Baltic States and Finland, with the E67 going due north through the gap to Kaunas and the second route running north-north-east to Vilnius. If this town is captured, then overland resupply or reinforcement to the Baltic States would become difficult in the extreme.
Taking the direct route between the two borders would be difficult because both Russia and Belarus have large national park forests directly adjacent to each other limiting their exit routes severely. The terrain in-between from Suwalki north to the Polish border and then 20 kilometers into Lithuania is tortuous off-road for vehicles as it is made up of many small but steep-sided hills.
Trying to traverse these hills when wet would see armored vehicle slide sideways. Wheeled vehicles would always be in danger of toppling over. So, routes are either in the small narrow valleys or straight up and down. Here the woods and forests are smaller, mostly 1-10 kilometers wide in size.
But these forests are everywhere and follow geographical patterns and logic from thousands of years of history. There are also many lakes, rivers, and streams in the valleys. Visibility can often be just a few hundreds of meters. Having a GPS may tell you where you are but won’t help you get where you want to go.
Defending this area is difficult as the enemy could be close but out of the scope of any direct fire weapons. But because the Polish-Lithuanian border is the shortest route, it still may seem the easiest route although it will be no sinecure for any attacker.
The northern route through Lithuania is also long and can be split into two. The southern half below the Vilnius road which runs directly adjacent to northwest Belarus is a heavily wooded national park.
The Vilnius road along its length averages 30 kilometers from the Belarus border and is 140 kilometers long. The good roads through the park are few but the sheer scale of the supply route provides any attacker from Belarus ample opportunity to seize and control it. The northern half of this area is primarily flat Lithuanian agricultural plain centered on Marijampole on the E67. It has flat open cornfield vistas often 100 square kilometers in area.
But again, everywhere you look the area is surrounded by endless lines of forest. Trying to fight using direct fire weapons here will be challenging as it means presenting yourself in the open to the enemy to get close enough for a firefight.
Other operational considerations must be the Russia-Russia railway that transits through Vilnius and the fact that both Kaliningrad and Belarus have training areas near the borders where exercising troops could change quickly to operational modes.
How many troops Russia would have for this operation is a serious question, and it depends upon the overall strategic play at the time, not to mention the willingness of Belarus to go to war. True, the Russian Western District has many troops but getting them into Belarus and into attack formation would be an obvious, time-consuming, and vivid warning sign for NATO. Kaliningrad can also not leave itself naked and many troops may be needed elsewhere. So Russia may need to rely on what is there available now. As the Belarus army at just 45,000 in total is small, it may not be enough.
Neither the Russians nor Belarussians would find closing and then holding the gap a simple activity. They must take Augustow and also cut both routes in more than one place or they could be circumnavigated through the complex terrain. They will also find fighting here difficult as the terrain makes large scale brigade-sized maneuvers difficult.
Trying to make Soviet-like operational thrusts will be risky, as, apart from the open north, the terrain does not lend itself to clean movement. It would be bloody in wet or snowy conditions. In some areas, centralized command and control, and good radio communications may even be impossible.
With their less robust training and vastly more centralized thinking, on paper, both armies should be vulnerable to well-conducted NATO maneuver warfare. Of course, they could try and control the corridor by fire. But this means near-constant surveillance and a huge expenditure of ammunition. Both could prove problematic.
But what they have shown from Donbas is that Russians are willing to let battalion groups off the leash and fight as they see fit. The question is if the Kaliningrad troops have the same training and motivation to drive a hard battle in hard conditions for an uncertain objective. What we know from Ukraine is that they have developed the scale and scope of their artillery support more than NATO. They also outrange us severely, especially with rocket launchers.
They are using drones extensively for observation and with artillery are continuously perfecting response times. Their use of electronic warfare is developing rapidly, especially for identifying units and locations. This would be a serious advantage for their forces. The Russians have also shown an ability to bring down drones. This means thinking more about purchasing cheap and easily replaceable drones and more sensors.
Polish and U.S. troops take part in the so-called Defender-Europe 20 joint military exercise at Drawsko Pomorskie training grounds in Poland on June 17, 2020. (AFP)
Russia will be expecting to kill drones so we must have redundancy at all levels. Brigades need something that flies high enough to be out of close air defense range.
They are also likely to try a heliborne coup de main on a key part of the E67 highway. If they do this they must be starved and isolated immediately.
The weakness Russia has is their lack of desire to close with the enemy. This has been shown graphically time and time again in Ukraine. Their small team tactics are poor and often no better than frontal attacks hiding behind a tank or BMP.
There is little to suggest that any Belarus forces would fight any better.
The key to defense, therefore, follows understanding and using complexity theory of how to deal with complex problems and chaos. This says that in circumstances like these we need to sense, probe, and react. Static defense or waiting is simply not an option, the area is too large and attack routes too many. The sheer size of the area to be covered demands that the fight will be at battalion and possibly even company level.
There will often be little time for deliberate actions as the enemy holds the initiative. We need to out-sensor him at all levels and this means many more drones and ground recce troops than we have now.
We will need more scouts with agile recce vehicles and off-road bikes to look at routes through the terrain, especially judging the driveability of the ground and routes through forests. Mission command is vital at all levels. Maneuver to engage the enemy must be early and fast to stop them from getting a foothold on the main supply routes.
The chances of organizational fracture and need to change routes are high so all vehicles need paper maps either as the main means of orientation or backup to maps on notepads. This terrain demands that all soldiers can map read with competence and confidence. This is something we cannot be sure of now.
Indirect fire capability needs to increase.
We cannot assume an attack on a nice sunny day with close air support and wall-to-wall Fairchild Republic A-10 aircraft. They may likely be deployed elsewhere. There must be at least in every fighting company an artillery observer with communications, sensors, access to drone coverage, and authority to engage immediately. The fighting battalions need more mortars to be able to support each company independently.
Brigades need artillery regiments with at least 24 guns and a battery of rocket launchers, or they risk simply being unable to suppress the many potential targets or cover sufficient terrain. They must have the capacity for counter-battery fire and arguably, if we are to overmatch Russia, at much longer ranges than we can manage now.
Most importantly to support maneuver in the larger open spaces, they need a greater percentage of smoke rounds in the ammunition delivery and observers, and commanders skilled at deploying it. We also need the ability to lay anti-armor mines quickly, at least at battalion level and perhaps even at the company level.
Countering enemy drones is now a must both by electronic means and close air defense. The latter is also vital right down to the company level against the support and attack helicopters. Close air defense has been a poor relation for many years, but the lessons of Ukraine show it is vital.
NATO troops take part in Saber Strike military exercises on June 16, 2017, in Orzysz. (AFP)
In summary.
The gap, or corridor, is large and with complex geography. It will be no simple five-minute effort for Russia to block the two main highways and subsidiary routes. It would be a complex operation for both Russians and Belarusians and with no surety of success.
But equally, defending the gap will be a complex operation for NATO troops too. It demands many of the skills lost after the Cold War, and adjustment to the operational changes suggested by the war in Ukraine. We have become complacent about many support arms skills and attributes as they were not mainstream for Iraq and Afghanistan. We have arguably lost organizational balance. NATO interoperability is not helped as we create complex multinational organizations.
We need to study both this ground and the likely fighting methods, and learn from them, as we learned from studying the defense of the Fulda gap (in Germany during the Cold War).
