The conversation around sovereign defense capability usually starts with headline platforms such as the F-35 Lightning II or next-generation vehicle programs. Yet the resilience of those systems depends on thousands of specialist components and subassemblies sourced throughout the industrial base.

A large part of the resilience sits much further down the supply chain. By the time a vehicle reaches the front line, its real-world performance has already been determined by Tier 2 and Tier 3 suppliers. 

Yet across the U.S. defense sector, the focus has been on the risks tied to foreign dependency in critical technologies and raw materials, especially where supply chains can be disrupted by geopolitics, capacity limits or even economic pressure. 

That concern spans everything from rare earth minerals and advanced electronics to semiconductors and propulsion systems. As a result, it’s driving a stronger push for domestic manufacturing, supplier diversification, and more resilient defense supply chains.

Beneath the Surface

In defense procurement, sovereign capability is often reduced to where a platform is finally assembled. However, operational sovereignty is much broader than that. 

What really matters is whether the U.S. can maintain, repair, upgrade and sustain equipment without being exposed to fragile overseas supply chains when conditions are uncertain.

OEMs lead the headline programs, and it’s supported by smaller specialist manufacturers that quietly keep everything working. They bring the engineering depth, the process knowledge and the flexibility to adapt when requirements change — and in defense, they often do.

That becomes especially clear in mobility platforms. Steering and suspension systems are pushed hard in service with heavy loads, rough terrain, constant vibration and harsh environments. When something fails there, it stops being a manufacturing issue and becomes an operational one very quickly.

This is why the wider defense industry is placing renewed emphasis on resilient industrial participation and trusted supplier ecosystems. For instance, NATO’s updated Defense Production Action Plan calls for expanded industrial capacity, stronger defense-critical supply chains, and closer cooperation across allied manufacturing networks. 

Reshoring and Nearshoring 

Conversations around U.S. defense manufacturing have historically featured around the need to reshore, yet in practice, many critical capabilities cannot simply be rebuilt domestically overnight.

Some suppliers have spent decades developing specialist engineering expertise, tightly controlled manufacturing processes and highly specific application knowledge that is extremely difficult to replicate quickly elsewhere.

It’s essential, therefore, to strengthen domestic capability where it matters most, while building more resilient supply chains with trusted allies and nearshore partners. Just look at the after effects of the COVID-19 pandemic, which made it pretty clear how fragile highly fragmented global sourcing can be. Since then, geopolitical tensions, rising NATO demand, and stretched industrial capacity have all pushed the U.S. further toward building more regional and resilient supply chains.

For example, the U.S. has doubled down on domestic semiconductor investment through the CHIPS and Science Act, while defense programs, like the F-35 Lightning II, still depend on a highly international supplier network across the U.S., U.K., Italy, Australia, Canada and others. 

Here, resilience here isn’t about doing everything at home; it’s about having trusted partners across a stable, allied industrial ecosystem that meet strict U.S. operational, compliance and security requirements. 

Not Just Procurement Exercises

One of the biggest misconceptions in defense manufacturing is that resilience can simply be procured through contracts. Whereas supply chains are built over time through relationships, engineering trust and shared operational understanding, often across multiple countries and tiers of suppliers. 

The most successful defense programs tend to involve long-standing collaboration between OEMs and specialist suppliers. That’s because defense manufacturing has always worked differently to mainstream automotive production, for example. 

Volumes are lower, requirements evolve constantly and platforms often stay in service for decades. OEMs end up leaning heavily on specialist suppliers who can react quickly, tweak designs and stick around long after the first production run is finished. 

A lot of this work happens out of sight. The supply chain isn’t fully transparent end-to-end, so Tier 2 and Tier 3 suppliers often do essential work without much recognition, sometimes even within the industry itself.

That dynamic is easier to see in programs like the F-35, where a broad network of U.S. and allied suppliers is more visible than in most defense platforms. After all, what looks like a single aircraft or vehicle is actually the end result of a long, layered supply chain stretching far beyond the prime contractor. 

Reshoring and nearshoring both have a role to play in strengthening resilience, but the bigger picture is that capability still comes down to what sits underneath those final assembly lines.

At the end of the day, it’s about whether the wider ecosystem — especially Tier 2 and Tier 3 suppliers — is strong, flexible and connected enough to keep programs running reliably over time.

Roger Brereton is head of sales at Pailton Engineering Ltd.