Underground tunneling system has recently been utilized to have an asymmetric effect against some of the conventional adversary on earth. This system is used as a means to form an underground axis of advance. Although records of tunnel warfare go back more than 4.000 years, it reached its peak as a defensive system sometime between the two World Wars. French army built underground tunnels in Maginot Line to prevent massive German attacks. Japanese army also constructed tunnel systems in order to hide from American airstrikes and sneak suddenly into adversary’s line. The tunnels in Vietnam, one of the best examples of tunnel wars, still stands even today with all its impressiveness.

DAESH dug a complicated tunnel system in Iraq which enable them to retreat easily inside the tunnels. Tunnel system provides the ability to sneak behind the frontline and suddenly infiltrate any house or garden in urban areas and use them as a new fighting line.

Recently, during the Operation Olive Branch, new tunnel systems have been found which were used by PKK/PYD to be safe from air strikes and bombardments in the northwestern district of Syria, Afrin.

Underground structuring for military purposes became even more important today as screening, scanning and visualization technologies develop. With these new technologies, armies or warring parties can gather photographs and collect intelligence on the surface of their enemies. But underground tunnels as a shield of air strikes and a unique opportunity to operate safe from drones, GPS, and other intelligence gathering technologies. By nature they are invisible to satellite imagery and aerial photography, it is impossible to get adversary’s exact plans.

However, Turkish Armed Forces (TAF) recently and successfully developed its aerial surveillance system in country’s asymmetrical fight against PKK/PYD militants. By having a drone system with aerial photography capabilities, TAF has had the upper hand on PKK on the ground and underground. In March 2017, TAF purchased six TB-2 type armed drones laden with MAM-C and MAM-L types mini smart munitions.

The importance of tunnels in warfare from the point of protection from GPS and satellite technologies is very well appreciated in the first week of Operation Olive Branch’s Mount Bursaya part. TAF discovered tunnels that extend along for dozens of kilometers at the strategically important Mt. Bursaya in northwestern Syria. These concrete tunnels consist of 90 centimeters thick walls, in two diameters and spans about 2 kilometers long. This tunnel system used to connect observation towers and reinforced emplacements to each other.

    

In the first part of the Mount Bursaya operation, TAF and FSA forces inflicted huge casualties on the frontlines that deployed at the top of the Mountain. Forces, then, succeeded to reach the center from the east. However, PKK terrorists had the advantage of logistics and ambush which they gather by the virtue of tunnels and they repelled the first wave of TAF’s and FSA’s attacks and made them retreat.

The underlying reason for this retreat was 3km-long tunnel system which was built by PKK. Those systems lie down in the north-south axis of the east side of the mountain and each part of it is connected to each other by foxholes.

It’s obvious that PKK has no intention to win the fight in Afrin by military means. It can be understood from the way that how they built such reinforced concrete tunnel systems and foxholes in the frontline.

PKK, in terms of defensive war and even as being a hybrid organization has a pretty low amount of infantry forces. Although this inferior situation of terrorist organization aims to harm aligned forces as much as it can. It can be understood from the counter-attacks that they use anti-tank missiles. As against to type of attacks of the terrorist organization inside Turkey, PKK’s militants avoid in Afrin to be in close battle against the TAF. Instead, they prefer to target Turkish armored vehicles remotely by using anti-tank systems which bring a new dimension to guerilla warfare in the region. The terrorist organization generally uses Russian Kornet type anti-tanks systems.

If asymmetrical warfare stands the test of time in the near future, tunnels will most probably remain as the most important part of the wars. As conventional powers have informational superiority provided by aerial surveillance, militants will prefer to maintain their activities underground. On the other hand, by the means of all technological developments and TAF’s aerial surveillance superiority, PKK has had to change its operational tactics at its defensive war in Afrin.