Geopolitical Risk and the ECB 2026 Reverse Stress Test: Mapping Failure Pathways Before It’s Too Late

Read our previous blog on ECB 2026 Geopolitical Reverse Stress Test.

Why This Matters

For banks, the ECB’s 2026 thematic reverse stress test on geopolitical risk is more than a regulatory exercise. It’s a reality check on failure pathways. The cost of missing how shocks transmit through your business can be severe: capital depletion, liquidity strain, and reputational damage when the next crisis hits.

This is not about ticking boxes or plugging in generic macro scenarios. It is about demonstrating to supervisors and to your board that you understand which channels could break your business model and how those channels map to tangible impacts on capital, liquidity, and operations.

In reverse stress testing, you start from a pre-defined failure outcome and work backwards to plausible scenarios that could cause it. In our previous blog, we argued for a bank-specific taxonomy of geopolitical risk drivers because reverse stress testing is only credible when the transmission channels are correctly selected and explained. Today, we take the next step: translating a risk driver into business‑model impact that can credibly produce the failure condition.

Worked Example: Military Escalation

In the context of Military Escalation, as an illustrative example, let’s consider a conflict disrupting shipping lanes in the South China Sea. The chain of transmission may unfold as follows:

• The incident would disrupt global trade routes, creating severe supply chain¹ bottlenecks and driving up costs for  industries depending on imports from and exports to the region. These disruptions would ripple through the real economy, affecting manufacturing, logistics, energy and semiconductor² sectors, and ultimately impacting banks with concentrated exposures in these sectors.

• Investors would seek safe assets, triggering sharp movements in commodity and foreign exchange markets. Banks with open positions in these markets could face significant mark-to-market losses, while liquidity strains emerge as funding costs rise. In addition, cargo insurance premiums on conflict‑adjacent corridors can spike, prompting re-routing and a broader repricing of risk.

• Operational risks would likely increase. Military tensions often coincide with heightened cyber and/or physical threats, increasing the likelihood of state-sponsored attacks on financial infrastructure. Banks would need to increase investment in cyber defence and resilience measures.

• Sanctions may be imposed by multiple parties, exposing banks to potential breaches and contractual disputes with counterparties linked to conflict zones. This adds complexity to transaction screening and legal oversight.

• Finally, these channels translate into measurable risk parameters. Credit portfolios tied to vulnerable sectors would see severe PD shocks, alongside LGD adjustments for collateral impacted by trade restrictions. Together with the market and operational risk impacts described above, they could erode CET1 ratios, revealing failure pathways that standard stress tests might miss.

Reverse The Logic

Because a reverse stress test starts from the outcome, the final step is iterative - the engine room of the exercise. To reach the targeted impact (300 bps CET1 depletion in the ECB’s thematic exercise), you will likely cycle through the channel, mechanism, risk‑parameter mapping and tune the shocks, strengthening or weakening their severity and duration until the constellation of assumptions consistently delivers the failure condition. But a key fallacy is to treat this as a mechanic “tuning” exercise rather than a careful consideration of which combination of shocks and channels that plausibly will drive CET1 below the threshold?

Scaling This Approach

The method extends to other relevant drivers: sanctions, energy disruptions, cyber threats, but the taxonomy must be granular and defensible, with a clear line‑of‑sight from event to channel, and then to portfolio, risk parameters and capital metrics. This strengthens Reverse Stress Testing credibility and ICAAP alignment, and produces governance‑ready narratives for senior decision‑makers.

How We Can Help

We support banks in building a robust RST framework. Our approach includes:

• Advisory support to design a purposeful, bank-specific taxonomy and link it to ICAAP.
• Quantitative modeling to support or benchmark scenario design.
• Hands-on assistance during stress test exercises, leveraging our experience with several European banks.
• Tool development and deployment of our Credit Risk Suite (CRS) for scenario modeling, automated ECL and CET1 impact calculations, and advanced scenario building.

With Zanders, you can move beyond compliance to create a stress test framework that enhances your strategic capability.