There has been a quantum jump in infrastructure development along our northern borders under the Narendra Modi government, particularly road communications and airfield upgrades. While the initial plan to improve border roads to achieve parity with China was conceived by the Congress-led UPA government in 2007, since 2014 the present government allocated a bigger budget and displayed tremendous drive in execution to extend these roads all the way to the Line of Actual Control. Chinese intrusions in April-May 2020 and the subsequent large-scale deployment of troops made it a compulsion.

Interestingly, the construction of roads up to the LAC without precautionary deployment of troops was one of the factors behind the success of China’s pre-emptive offensive manoeuvre in April-May 2020 and India’s loss of control over 1,000 square kilometres of territory in Ladakh.

The Director General of Border Roads, Lt Gen Rajeev Chaudhry, has expressed optimism that India will catch up with China in terms of road communications within the next three to four years. However, a comparative assessment of border infrastructure by India Today suggests that we still have a long way to go. As per my assessment, the protection of permanent defences and logistical infrastructure has also not kept pace with the evolving battlefield dynamics dominated by Precision Guided Munitions (PGM) and drones.

Modern surveillance/reconnaissance means in the form of satellites, aircraft , drones, radars and electronic interception can pinpoint all targets on the battlefield. These can then be targeted by air/ground-based PGMs and drones with over 90 percent hit probability. Electronic and cyber jamming to neutralise command and control, fire control means and missiles/munitions further compounds the threat.

The ongoing Russia-Ukraine war is a good example of the technological battlefield. However, the issue is relative and there are both active and passive countermeasures for all types of threats. In such an environment, a well protected defender has a distinct advantage over the attacker who is forced to manoeuvre in the open to capture territory. Unless the technological asymmetry is overwhelmingly disproportionate, technology alone cannot assure defeat and capitulation of a relatively weaker defender.

The military differential between India and China is predominantly in the domains of cyber and electronic warfare and in the quality and quantity of PGMs, drones, and missiles. Until India can bridge this gap, it would be prudent to rely on an active defensive strategy at the strategic level to stalemate China while retaining the ability for tactical offensive.

It is pertinent to reiterate that decisive wars between nuclear-armed states are passé, and the probability of even a limited war is very low. However, below the nuclear threshold, there is ample scope for the use of stand-off air/ground-based PGMs and drones, as well as electronic and cyber attacks, without resorting to physical attacks. Currently, India’s retaliatory capacity, in terms of both quantity and quality, is not at par with China.

In such an environment, well-protected defences and underground logistical installations can significantly neutralise China’s superiority. Tunnelling is one of the most cost-effective means to achieve this.

Tunnel warfare goes back 4,000 years, and has been employed for both offensive and defensive purposes. In the last 200 years, the emphasis on mobility, initially with cavalry and later with mechanised and airborne/heliborne forces, reduced the efficacy of tunnel-based fixed defences. A notable example is how the German Blitzkrieg bypassed the heavily fortified Maginot Line in France, in World War II.

However, tunnel warfare continued to be effectively utilised by the defender to neutralise the asymmetry in air and ground firepower of their adversaries. The Chinese are masters of tunnel warfare and pioneered its revival during the Sino-Japanese War in 1937-45. In the village of Ranzhuang in Hebei province, which is a tourist attraction today, the Chinese dug 15 km of tunnels connecting the houses to foxholes on the battlefield, allowing them to attack Japanese soldiers from the rear. The Japanese learnt this art from the Chinese, and used it in the island battles in the Pacific. Battles of Peleliu and Iwo Jima islands, which were captured by the US Marines at a very heavy cost, are notable examples.

During the Korean War 1950-53, North Korean and Chinese forces built underground fortifications in semi-mountainous terrain to protect themselves from American airpower and artillery. These were so extensive that for every mile (1.6 km) of the front on the surface, there were two miles (3.2 km) of underground tunnels, that is, more than 300 miles (480 km) in total.

Vietcong guerrillas in Vietnam perfected tunnel warfare into an art. Oblivious of a Vietcong tunnel network in the area of Cu Chi near Saigon, the US forces constructed a 1,500-acre military base housing 4,500 troops over it. Shadowy figures emerged out of the tunnel to cause heavy casualties. The base was abandoned and had to be bombed by the US Air Force and then physically cleared after suffering heavy casualties. Even modern-day terrorists have exploited tunnels for guerrilla warfare in Afghanistan, Syria, and along the Israel-Palestine border.

I have laboured on these historical examples to underscore the effectiveness of tunnels for protection, as they expose the limits of PGMs, often forcing states to resort to highly destructive measures: B-52 bombers in Vietnam, GBU-43/B Massive Ordnance Air Blast (MOAB or Mother of All Bombs) in Afghanistan, and massive airstrikes in Israel. Yet, the subterranean domain remains under-researched, poorly understood, and often underestimated. Therein lies a critical lesson for the defence of our northern borders.

Currently, our mountain defences are designed to withstand suppressive fire from small arms and non-PGM artillery, with their effectiveness further reduced due to reverse slope defences. Defences on dominating heights can withstand conventional firepower and the defender has a distinct advantage over the attacker, who is exposed and forced to attack uphill in rarefied atmosphere.

However, the design of these defences, which stand out like sore thumbs on hill tops, has remained largely unchanged for over a century. Such defences will be obliterated by stand-off ground or air-delivered penetrator PGMs, including drones. Classic close combat is passé. The People’s Liberation Army (PLA) will neutralise the ‘predominance of the defence’ in high altitude terrain by not getting involved in “close combat” over unfavourable terrain. If at all it chooses to use force to physically capture ground, its pattern of attack will be driven by high-end technology with overwhelming use of PGMs, cyber, and electronic warfare. The much romanticised ‘blood and guts’ close combat is a relic of the last century. Stand-alone destruction of posts and logistical installations may also be undertaken as punitive measures without resorting to physical attacks. Logistical installations in the open are also sitting ducks for PGMs.

Given the PLA’s overwhelming superiority in cyber and electronic warfare, as well as the quality and quantity of offensive and defensive means in terms of PGMs, drones and missiles, achieving parity will take a long time considering our relatively modest budget, which is unlikely to be increased substantially anytime soon. Tunnel warfare offers a cost-effective interim solution to stalemate and counter both physical and standoff attacks.

Recent reports indicate that the PLA is constructing underground installations, possibly for logistics, communication centres, nuclear weapons, or higher headquarters command posts, about 60-70 km from the LAC opposite the DBO Sector. I sincerely hope that the Indian Army has drawn the correct lesson: the necessity of adopting tunnel warfare for permanent defences, logistical installations, communication centres, command posts, and air assets.

Despite speculative reports, it is my assessment that the Indian Army has not formally embraced tunnel warfare as a tactical concept. High-altitude terrain is tailor-made for tunnel warfare. The Army should promptly conduct a comprehensive study to explore the potential of tunnel warfare for our permanent defences in mountains. Army engineers should examine models such as the defences along the 38th parallel in South Korea and adapt them uniquely to our needs for living and fighting in high-altitude terrain. Similarly, logistical installations must go underground, as in their present state, they will perish in 24-48 hours of battle.

Tunnel warfare has been successfully exploited to neutralise resource and technology asymmetries, and I find no logical reason why the Indian Army should not do so.