artillery support, and even irregular troops to prop up a supposed independence movement along its border.53 Both nations are conducting a low-intensity struggle with the United States in cyberspace, with China stealing the U.S. government personnel database in 2015 and Russia hacking into the electronic files of the Democratic National Committee and Clinton campaign leaders in 2016. Even if nuclear weapons and American hegemony render direct conventional war less likely, nations will still pursue their interests by coercing other states.
Rogue states, as the Clinton and Bush administrations called them, or “states of concern” in the Obama years, compound these threats to international peace and stability. Whatever their name, these autocratic states both oppress their own populations and threaten their neighbors. North Korea, for example, remains one of the most extreme dictatorships on earth, with a population deprived of basic services and subject to famine and starvation, an oppressive police state, with one of the world’s smallest per capita GNP. At the same time, the Kim regime devotes the lion’s share of its budget to its armed forces. North Korea maintains the fifth largest army in the world and it periodically launches attacks on South Korea, such as the 2010 sinking of a South Korean warship.
Iran has joined North Korea in challenging the regional status quo with a level of hostilities that fall short of outright war. Iran supports religious militias such as Hezbollah, which harasses Israel from southern Lebanon, and sends irregular troops to support the Assad regime in the Syrian civil war. It supported Shiite militia groups during the Iraq war. Both Iran and North Korea bolster their revisionist agendas with programs to develop nuclear weapons and ballistic missiles, which would allow them to pursue their unconventional attacks without fear of reprisal. Their programs could spark a nuclear arms race in the Middle East, where Saudi Arabia and Egypt might seek to match Iran, or in East Asia, where Japan and South Korea might develop nuclear deterrents. Rogue nations refuse to abide by the basic principles of the international system and may seek to export revolution or disrupt the existing order. Yet, their autocratic natures and revolutionary worldviews make them less susceptible to diplomatic or political pressure.
Some nations may bear ill will toward the United States, such as Venezuela, but have few military means to inflict harm. Only very limited American force could be justified to forestall a threat from Caracas. Other nations, however, such as North Korea, present themselves as rivals and are acquiring the means to attack. Pyongyang still considers itself at war with the U.S. and South Korea and holds the national goal of expelling American troops and forcibly unifying the peninsula under its regime. While the Kim regime has held the capacity to attack American troops stationed in South Korea since 1953, it posed no military threat to the continental United States. In 2016, however, North Korea successfully tested a 10-kiloton nuclear weapon, and in 2012 it launched a satellite into low-Earth orbit—the technology necessary to develop a ballistic missile capable of striking North America.54 As the magnitude of the harm posed by Pyongyang has increased dramatically (nuclear weapons), and the likelihood it could execute an attack is rising sharply (ballistic missiles), the United States could legitimately employ more destructive means to squelch the threat of a North Korean attack. More precise weapons may give the United States the means to degrade or eliminate a North Korean nuclear threat without causing the wider harm that might trigger a broader war.
The pace of today’s most pressing international threats seems to be set by the disintegration of states and the rise of civil wars, the spread of terrorism, and the proliferation of WMD technology, as well as their negative spillover effects upon neighbors, or the international system as a whole. To be sure, the threat of conventional conflicts between states always exists, though the odds of a war between the great powers has receded since the end of World War II. While the chances of great power conflict have decreased, the capability to duplicate their destructiveness has expanded because of the spread of technology into less responsible hands. But technology may also present the means to curb these threats. New weapons technologies may provide western states with the ability to use more precise, focused force to punish oppressive regimes intent on genocide. They can allow nations to pursue terrorists into lands inaccessible by ground or sea units. They can raise the costs on rogue states seeking WMD or rising powers seeking to upend regional stability. To fully understand the reasons why new technology may succeed, we will now examine a useful theory to explain why force may help in keeping the peace.
Using Force to Commit to Peace
In order to control these threats, nations must return to the use of force as a means of coercion. Great powers have long used force to pressure each other. Even in the twenty-first century, nations will continue to advance their interests, at times with conflict, and at other times with cooperation. New military technologies will make it feasible for nations to use force more often, rather than less, because they will be able to achieve their aims without triggering broader war. In this section, we turn our attention to one possible theory that could help explain why expanding the methods of force could encourage greater peace between the great powers.
We do not adopt this approach as the sole foundation for our account of war, technology, and law, rather, we develop it as a possible theory that supports our intuition that advancing weapons technology can lead to less conflict. This theory sees war as the failure of rational nations to reach a settlement of their disputes. The anarchy of the international system undermines the bargaining process because nations have uncertain information about their opponents’ capabilities and cannot trust them to keep their promises. More ways to use force could provide leaders with greater means of signaling their seriousness of will, military capabilities, and commitment to avoid war. That may justify the counterintuitive conclusion that new technology can bring more, rather than less, peace.
Our world might be safer if it were more actively policed, just as more active policing has reduced violent crime in American cities.55 The international system, however, lacks an effective supranational government that can stop violence in the same way that domestic institutions maintain law and order at home. Not only must nations use force more broadly in self-defense, but in the absence of an effective government they must also intervene to prevent threats to global welfare from weapons of mass destruction, terrorism, and aggressive authoritarian nations. Rivals such as Russia and China pose a tough challenge for this mission. Both nations enjoy the resources and militaries to place them in the rank of great powers. Their ambitions clash with U.S. interests, from Eastern Europe to the seas of the western Pacific. While their intentions may make them rivals of the United States, however, their own economic status gives them a great deal to lose. American power likely deters them from any direct, widespread conflict.
Critics, on the other hand, believe that new weapons could make the use of force cheaper, and hence war more commonplace. But we believe this view is mistaken. The ability to use force more precisely will prove a benefit to the international system. The signaling of resolve and capability through less destructive attacks can help avoid the worldwide conflicts that caused such grave human suffering and death in the twentieth century. Ironically, the availability of new weapons technologies should reduce the chances of great power war and lead to more settlement of conflicts.
If there is a place for coercion (as opposed to merely repelling attacks), however, the scope for resort to force must be enlarged. It will no longer be obvious that retaliatory measures must actually be limited to attacks on “military objectives.”56 Keeping the peace today requires a return to earlier understandings of the use of force. International law should allow nations to use force against civilian targets, so long as they do not involve lethal means of coercion. Recent efforts to apply a broad definition of the principle of distinction to twenty-first century conflicts should be relaxed, because they will have the unintended and perverse consequence of rendering war more likely and more destructive.
Even if our approach were to allow the great powers to suppress WMD proliferation, humanitarian crises, and terrorism, critics will worry that it will encourage conflict. Wider discretion in the use of force will result in more violence, which could increase the risks of war. Close attention to a promising theory of international crises, however, suggests
