In a recent Times column, Juliet Samuel suggested that gestures of non-aggression—such as Finland’s 2015 destruction of its one million landmine stockpile—now appear dangerously naïve. Ukraine, for its part, has rightly disregarded the Ottawa and Oslo (banning cluster munitions) conventions. Its survival depends on ingenuity, rapid technological development (for instance through the work of funds such as D3), and collaboration with its allies to prototype and deploy advanced systems.
Reinhold Niebuhr, in Moral Man and Immoral Society, contends that to be moral, one must possess the capacity for force—‘power must be challenged by power.’ That power, however, must be exercised with responsibility, humility, and moral purpose. Nigel Biggar, my former doctoral supervisor and a key figure in the Niebuhr tradition of Christian realism, argues in In Defence of War that war can be justified on balance when it meets the criteria of jus ad bellum: just cause, legitimate authority, right intention, proportionality, and reasonable prospect of success.
War, in this reading, can express a ‘kind harshness’—a form of judgment exercised in defence of victims. Like Niebuhr, Biggar grounds his argument in Augustinian realism: the world is fundamentally good, yet broken. Because evil persists, the moral use of force becomes necessary to uphold what is right. I believe this to be true, and directly applicable to the national security-focused world in which we find ourselves.
What does this mean then for Western countries as national security reasserts itself as the central organising principle of governance?
It means significant and urgent investment in defence and deep technology, including for instance emerging capabilities like cognitive warfare and neuroadaptive systems (wearables that enhance soldiers’ performance in live combat), counter-drone systems for urban, rural, and maritime environments, and next-generation electronic warfare and geospatial intelligence.
If drone attacks intensify at sea—such as those carried out by the Houthis to disrupt global shipping routes—counter-drone systems will be vital to ensure safe passage. In a world of manipulated narratives and disinformation, geospatial intelligence will serve as a source of truth, helping establish what is actually happening on the ground. And as agentic AI grows increasingly capable of manipulating users—through sycophancy, persuasion, and other techniques—oversight technologies like Yoshua Bengio’s new LawZero project will be essential for maintaining objectivity and integrity.
The responsible use of force today precludes pacifism, averting violence altogether. It means maintaining—and advancing—the capability for overwhelming force, so it is ready if needed. Morality in an era of national security demands investment in defence technologies at speed, to stay several steps ahead of adversaries. A ‘whole-of-society’ approach, as recommended in the recent UK Strategic Defence Review, means preparing citizens with such a mindset. Restraint and humility are still critical virtues—but must not be mistaken for weakness. Western nations must be prepared to act swiftly, decisively, and with the deterrent power that peace requires.
This is the world we are entering: one in which governments and civilians alike must be ready for unexpected threats. The hum of a drone overhead is more than a sound—it is instead a warning, reminding not only Ukrainians but those currently in peaceful situations, to prepare ourselves for potential conflicts to come. The appropriate response is not retreat, but the responsible and moral exercise of power: a necessary duty if we are to preserve peace, freedom, and justice in a world increasingly intent on contesting them.