The increasingly common “preventive” use of military force raises difficult moral and legal issues that seriously challenge prevailing international law. Despite the justifying rhetoric alleging that these anticipatory wars aim to increase or ensure peace and security, such wars pose both moral and political dilemmas. Even when a war is declared in self-defense in response to an actual or imminent show of aggression, it is possible to take a principled pacifist or utilitarian stance instead of resorting to violence. While the long-standing just-war doctrine sanctions military self-defense, and international law endorses it, preventive wars in the name of self-defense when the danger is not actual or imminent raise moral conundrums and lead to problematic outcomes. Also, moral and military hazards of “rescue” wars are compounded when they are preventive wars against anticipated evils. The recent trend of justifying preventive war by blurring the distinction between preemption and prevention with epithets like “gathering threats” does little to clarify the important issues that arise.

The conundrum of whether nations should adhere to existing international law or carry out illegal but morally justified intervention is not new in the context of egregious violation of negative human rights by certain regimes. For instance, illegal intervention in the name of an urgent humanitarian cause occurred in the NATO bombing of Yugoslavia in 1999. But nations hide behind international law in their reluctance to undertake military intervention to enforce basic rights of subsistence. Certainly it is true that raising high barriers to intervention and respecting sovereignty minimizes self-serving military interventions couched in moral rhetoric. If interventions were permitted in inept or failed states in response to their ineptitude, then there would be no limit to military operations, posing a grave threat to the stability of world order. Consequently, “non-interventionism” is the standard thrust of international law, with “reluctant interventionism” being the practice only in exceptional cases.

The increasingly common “preventive” use of military force and the tragic dilemmas of recent military operations have severely challenged international law in regard to the justification of waging preventive wars for self-defense and under the guise of international peace and security. Also, the growing trend of justifying preventive use of force by invoking principles of the just-war doctrine has left the just-war theorists wondering whether the theory itself is in need of a fundamental shift. This chapter responds to these concerns by placing the debate in the wider discourse of global justice. By invoking the concept of just peace, I discuss prevention from a non-interventionist perspective and show how it can be an effective measure for national security as well as for humanitarian policies. I call this approach “preventive non-intervention” and explain how it is intimately tied to human rights concerns. The best way to prevent a crisis is to ensure justice and fair representation in global governance, for which other means than the use of military force are more prudent and effective. An emphasis on global justice underscores the need for a preventive approach that is non-interventionist; it calls for rooting out the underlying causes of conflict, injustice, and humanitarian crises by a collaborative system of just governance through institutional implementation of rights. The focus is on being proactive by getting involved in issues of economic justice and inclusive democratic-political processes both within countries and especially in the global order.