In the past, predictions about future warfare have often put too much emphasis on new technologies and doctrines. In the 19th century the speedy victory of the Prussian army over France in 1870 convinced European general staffs that rapid mobilization by rail, quick-firing artillery and a focus on attack would make wars short and decisive. Those ideas were put to the test at the beginning of the First World War. The four years of trench warfare on the western front proved them wrong.
In the 1930s it was widely believed that aerial bombardment of cities would prove devastating enough to prompt almost immediate capitulation. That forecast came true only with the invention of nuclear weapons a decade later. When America demonstrated in the first Gulf war in 1990-91 what a combination of its precision-guided munitions, new intelligence, surveillance and reconnaissance methods, space-based communications and stealth technology could achieve, many people assumed that in future the West would always be able to rely on swift, painless victories. But after the terrorist attacks on America on September 11th 2001, wars took a different course.
This special report will therefore offer its predictions with humility. It will also limit them to the next 20 years or so, because beyond that the uncertainties become overwhelming. And it will not speculate about the clear and present danger of war breaking out over North Korea’s nuclear weapons, which with luck can be contained. Instead, it will outline the long-term trends in warfare that can be identified with some confidence.
In the past half-century wars between states have become exceedingly rare, and those between great powers and their allies almost non-existent, mainly because of the mutually destructive power of nuclear weapons, international legal constraints and the declining appetite for violence of relatively prosperous societies. On the other hand, intrastate or civil wars have been relatively numerous, especially in fragile or failing states, and have usually proved long-lasting. Climate change, population growth and sectarian or ethnic extremism are likely to ensure that such wars will continue.
Increasingly, they will be fought in urban environments, if only because by 2040 two-thirds of the world’s population will be living in cities. The number of megacities with populations of more than 10m has doubled to 29 in the past 20 years, and each year nearly 80m people are moving from rural to urban areas. Intense urban warfare, as demonstrated by the recent battles for Aleppo and Mosul, remains grinding and indiscriminate, and will continue to present difficult problems for well-meaning Western intervention forces. Technology will change war in cities as much as other types of warfare, but it will still have to be fought at close quarters, block by block.
Even though full-scale interstate warfare between great powers remains improbable, there is still scope for less severe forms of military competition. In particular, both Russia and China now seem unwilling to accept the international dominance of America that has been a fact of life in the 20 years since the end of the cold war. Both have an interest in challenging the American-sponsored international order, and both have recently shown that they are prepared to apply military force to defend what they see as their legitimate interests: Russia by annexing Crimea and destabilising Ukraine, and China by building militarised artificial islands and exerting force in disputes with regional neighbours in the South and East China Seas.
In the past decade, both China and Russia have spent heavily on a wide range of military capabilities to counter America’s capacity to project power on behalf of threatened or bullied allies. In military jargon, these capabilities are known as anti-access/area denial or A2/AD. Their aim is not to go to war with America but to make an American intervention more risky and more costly. That has increasingly enabled Russia and China to exploit a “grey zone” between war and peace. Grey-zone operations aim to reap either political or territorial gains normally associated with overt military aggression without tipping over the threshold into open warfare with a powerful adversary. They are all about calibration, leverage and ambiguity. The grey zone particularly lends itself to hybrid warfare, a term first coined about ten years ago. Definitions vary, but in essence it is a blurring of military, economic, diplomatic, intelligence and criminal means to achieve a political goal.
The main reason why big powers will try to achieve their political objectives short of outright war is still the nuclear threat, but it does not follow that the “balance of terror” which characterised the cold war will remain as stable as in the past. Russia and America are modernising their nuclear forces at huge expense and China is enlarging its nuclear arsenal, so nuclear weapons may be around until at least the end of the century. Both Vladimir Putin and Donald Trump, in their very different ways, enjoy a bit of nuclear sabre-rattling. Existing nuclear-arms-control agreements are fraying. The protocols and understandings that helped avert Armageddon during the cold war have not been renewed.
Russia and China now fear that technological advances could allow America to threaten their nuclear arsenals without resorting to a nuclear first strike. America has been working at a concept known as Conventional Prompt Global Strike (CPGS) for over a decade, though weapons have yet to be deployed. The idea is to deliver a conventional warhead with a very high degree of accuracy, at hypersonic speeds (at least five times faster than the speed of sound), through even the most densely defended air space. Possible missions include countering anti-satellite weapons; targeting the command-and-control nodes of enemy A2/AD networks; attacking the nuclear facilities of a rogue proliferator such as North Korea; and killing important terrorists. Russia and China claim that CPGS could be highly destabilising if used in conjunction with advanced missile defences. Meanwhile they are developing similar weapons of their own.
Other potential threats to nuclear stability are attacks on nuclear command-and-control systems with the cyber- and anti-satellite weapons that all sides are investing in, which could be used to disable nuclear forces temporarily. Crucially, the identity of the attacker may be ambiguous, leaving those under attack uncertain how to respond.
Rise of the killer robots
At least the world knows what it is like to live in the shadow of nuclear weapons. There are much bigger question-marks over how the rapid advances in artificial intelligence (AI) and deep learning will affect the way wars are fought, and perhaps even the way people think of war. The big concern is that these technologies may create autonomous weapons systems that can make choices about killing humans independently of those who created or deployed them. An international “Campaign to Stop Killer Robots” is seeking to ban lethal autonomous weapons before they even come into existence. A letter to that effect, warning against a coming arms race in autonomous weapons, was signed in 2015 by over 1,000 AI experts including Stephen Hawking, Elon Musk and Demis Hassabis.
Such a ban seems unlikely to be introduced, but there is room for debate about how humans should interact with machines capable of varying degrees of autonomy, whether in the loop (with a human constantly monitoring the operation and remaining in charge of critical decisions), on the loop (with a human supervising machines that can intervene at any stage of the mission) or out of the loop (with the machine carrying out the mission without any human intervention once launched). Western military establishments insist that to comply with the laws of armed conflict, a human must always be at least on the loop. But some countries may not be so scrupulous if fully autonomous systems are seen to confer military advantages.
Such technologies are being developed around the globe, most of them in the civil sector, so they are bound to proliferate. In 2014 the Pentagon announced its “Third Offset Strategy” to regain its military edge by harnessing a range of technologies including robotics, autonomous systems and big data, and to do so faster and more effectively than potential adversaries. But even its most ardent advocates know that the West may never again be able to rely on its superior military technology. Robert Work, the deputy defence secretary who championed the third offset, argues that the West’s most enduring military advantage will be the quality of the people produced by open societies. It would be comforting to think that the human factor, which has always been a vital component in past wars, will still count for something in the future. But there is uncertainty even about that.
(This article appeared in the Special report section of the print edition under the headline “The new battlegrounds”)