A senior Dutch limited partner has a warning for the investors rushing to fold defence into their sustainability mandates: do not mix up sustainability and security. The two have become entangled in European allocation debates as governments push for rearmament and capital looks for a home in the defence sector, but treating them as the same thing, the LP argues, risks muddling two mandates that answer to different goals and different stakeholders.
The pressure to blur the line is real. Russia's war in Ukraine and a more uncertain security environment have pushed European defence spending sharply higher, and asset owners are being asked, sometimes by their own governments, to view investment in weapons and military supply chains as a public good. At the same time, many of those same institutions run sustainability frameworks that for years excluded or limited defence exposure. The result is a collision between a renewed strategic case for security spending and a decade of responsible-investment policy built partly on keeping arms at arm's length.
Two mandates, two logics
The Dutch LP's point is that conflating the two does a disservice to both. Sustainability investing, at its core, is about managing long-horizon environmental and social risk and steering capital toward outcomes a fund's beneficiaries endorse. Security investing is a strategic and geopolitical judgement about national and regional defence. Calling defence spending sustainable because it is currently necessary stretches the word past usefulness, and it invites the kind of definitional drift that has already drawn criticism toward the responsible-investment industry.
That matters for credibility. Sustainability frameworks have spent years fighting accusations of vagueness and greenwashing. Quietly redefining defence as sustainable to accommodate a political moment would hand critics more ammunition and weaken the standards that make the label mean anything. An LP can decide to invest in defence on strategic or return grounds without needing to file it under sustainability, and being honest about which box a decision belongs in is part of keeping both boxes intact.
The allocator's dilemma
None of this means defence is uninvestable. The Dutch LP's argument is about clarity, not exclusion. An institution can hold a clear-eyed view that defence is a legitimate, even attractive, allocation in the current environment, while still refusing to relabel it. The cleaner approach is to treat security as its own category with its own rationale, its own risk assessment and its own reporting, rather than smuggling it into an ESG sleeve where it does not naturally fit.
For European pensions and insurers in particular, the stakes are high because their beneficiaries and regulators are watching. A fund that tells its members it invests sustainably, then quietly counts missiles toward that promise, will struggle to defend the inconsistency. A fund that says plainly that it invests in defence for strategic and financial reasons, and separately maintains its sustainability commitments, has a far more durable position.
What it means for capital
The broader signal for allocators is that the defence reallocation now under way in Europe needs its own framework, not a borrowed one. As more capital moves toward security, the institutions that handle it cleanly, with defence assessed on its own merits and sustainability mandates left coherent, will avoid the reputational traps that catch those who try to make one label do two jobs.
The temptation to merge the two is understandable. It lets an institution satisfy political pressure to fund defence while preserving the appearance of an unbroken sustainability record. But the Dutch LP's caution is well placed. Definitions matter in this industry precisely because they are the foundation of trust between a fund and the people whose money it manages. Stretch them for convenience and they stop protecting anyone.
The practical takeaway is straightforward. Allocators weighing defence exposure should decide on the strategic and financial case directly, document it as security investing, and keep their sustainability policies separate and intact. The two can coexist in a portfolio. They should not be confused for each other on the page.