Defense Tech Investors Make Christian Just War Case for AI Weapons

Two prominent defense technology investors are framing the race to develop AI-powered weapons systems as a moral imperative, invoking centuries-old Christian ethics to argue that the United States must build autonomous military capabilities responsibly — and ahead of its adversaries.

Trae Stephens and Katherine Boyle, writing in The Washington Post, contend that just war theory — the ethical framework governing when and how nations may engage in armed conflict — doesn't prohibit new military technologies. Instead, they argue it creates an obligation for democracies to develop them first.

The opinion piece, published July 7, 2026, arrives as the U.S. defense establishment grapples with how quickly to integrate artificial intelligence into weapons systems while China and other nations accelerate their own military AI programs. The authors' argument represents a notable shift in how Silicon Valley figures are publicly discussing autonomous weapons, moving beyond purely strategic rationales to invoke moral philosophy.

The just war framework

Just war theory, rooted in Christian theological tradition and developed by thinkers including Augustine and Thomas Aquinas, establishes criteria for ethical warfare. The doctrine addresses both when war is justified (jus ad bellum) and how it must be conducted (jus in bello).

Stephens and Boyle's central thesis is that this framework doesn't merely permit but requires responsible nations to pursue advanced military capabilities. Their argument hinges on the principle that failing to develop AI weapons systems could leave democracies vulnerable to authoritarian adversaries who face fewer ethical constraints in their own development programs.

Why it matters

The debate over autonomous weapons has largely focused on technical safety concerns and international law. By grounding their argument in moral philosophy with deep roots in Western ethical tradition, the authors are attempting to reframe the conversation for policymakers and religious leaders who might otherwise oppose AI weapons development. This approach could influence how Congress and the Pentagon approach funding and oversight of military AI programs, particularly as concerns about China's military modernization intensify.

The deterrence argument

The authors frame their position around deterrence — the idea that possessing advanced capabilities prevents adversaries from acting aggressively. This logic has underpinned U.S. nuclear strategy for decades, and Stephens and Boyle are extending it to the AI domain.

Their argument implicitly acknowledges that AI weapons systems will be developed regardless of whether the United States pursues them. Given that inevitability, they contend, American leadership in the space offers the best chance for establishing norms around responsible use and technical safeguards.

Both authors have significant financial stakes in defense technology companies. Stephens is a co-founder of Anduril Industries, a defense startup valued at billions of dollars that builds autonomous systems for the military. Boyle is a general partner at Andreessen Horowitz, which has invested heavily in defense tech companies.

The opinion piece was first reported by The Washington Post and appears as part of the newspaper's Superintelligent newsletter focused on artificial intelligence developments.