When the Unthinkable Happens: Maintaining Operational Resilience Amid Geopolitical Instability

Introduction

In the world of IT and cybersecurity, we often talk about "five nines" of availability and regional redundancy. But what happens when the "unthinkable" occurs?

An AWS data center in the Middle East was hit by “objects”¹ on March 1st, 2026, a consequence of ongoing regional conflict, causing a regional blackout. Similarly, in September 2025², an undersea cable cut in the Red Sea caused a regional brownout event due to disruption in Internet access from Asia and Mideast to European and North American destinations. These events highlight the vulnerability of the modern internet infrastructure and cloud services that are  susceptible to service outages and performance issues whether due to man made or natural disasters.

In both these cases, Zscaler's infrastructure was not targeted and has remained mostly unaffected. However, outside of Zscaler’s service, our customers certainly felt the impact and we worked frantically to support them, minimizing the impact even though it was not related to the Zscaler environment.

Delivering high resiliency with the Zero Trust Exchange

The Zscaler Zero Trust Exchange is the industry's largest AI security platform, brokering more than 500 billion transactions daily, across its global platform of more than 160 locations globally.

The Zscaler Zero Trust Exchange platform delivers exceptional resilience, guaranteeing 99.999% availability and uninterrupted security and connectivity—even when individual data centers fail, networks get congested (brownouts), or entire regions go dark (blackouts). Our globally distributed footprint, automated cloud operations, and built-in failure protections work together to maintain secure, low latency access for AI and machine workloads, users and things under any of the failure scenarios to the content and applications needed to enable modern businesses.

Zscaler’s cloud infrastructure is built with high resiliency to absorb most backend system failures from impacting the end users and our customers’ operations. However, certain classes of failures like blackouts, brownouts, and critical failures primarily affecting traffic flow via the Zero Trust Exchange can end up to be customer impacting. Zscaler ensures we support our customers with tools to detect, mitigate and recover from these impacts quickly.

Blackouts represent a complete failure of a data center or an entire data center region, like the incident that affected AWS customers in the UAE. Since Zscaler does not rely on that AWS region, it was unaffected. However, in the past, a blackout event during Hurricane Sandy affected our NYC facilities several years ago. Similarly a total power outage at a partner colocation facility in London a few years back affected our customers in that region. Despite the severity implied by the term "blackout," Zscaler's monitoring capabilities quickly detected these situations—whether via a tunnel or a client connector.

Crucially, Zscaler has inbuilt switchover mechanisms that ensured automatic recovery by failing over to an alternative data center in both these instances. Thanks to Zscaler’s rigorous capacity planning methodology, all data centers maintain sufficient service and network capacity headroom. This proactive measure ensures that failovers are seamless and effectively prevents the risk of cascading failures.

Brownouts occur when the Zscaler services are operating normally, but the shared responsibility area, including client premises,  client network path between a client and Zscaler, or Zscaler and a content provider is impaired for some reason. These disruptions can significantly impact the end user experience for some organizations, but not all and stem from various causes, including physical events like subsea cable cuts (as recently seen in the Red Sea) or sabotage, SaaS provider outages, network congestion, and ISP failures etc.

Mitigating these brownouts often relies on third-party providers and is outside the direct control of Zscaler and the customer. To minimize the impact, Zscaler offers critical, customer-controlled features such as latency-based data center selection and network path optimizations, along with continuous investment in its core network underlay. However, in specific situations, manual intervention is required, necessitating a close partnership and shared responsibility between Zscaler and its customers to identify the root cause and implement mitigation strategies—for example, pinpointing alternative customer ISPs with superior interconnectivity to Zscaler's transit providers.

For Zscaler, proactive detection of performance degradation is fundamental to minimize impacts – whether from external entities such as service and cloud providers – on the user experience. To illustrate the capabilities that our operations teams have at their disposal, here is a dashboard that represents the impact observed during the September cablecut situation in the Red Sea.

Our team promptly identified the root cause. It was latency spikes between the Zscaler BOM6 data center in India and Azure regions in Europe decisively ruling out  any local connectivity issues to the DC or any Zscaler service issue.

Subsequently, we were able to observe the individual impacted hops within the Microsoft network in the network centric view:

Zscaler operations teams gain this unique hop-by-hop visibility, representing the platform experience from the user point of view, by leveraging millions of anonymized ZDX probes generated by the Zscaler Client Connectors across the globe.

Critical Failures due to widespread cyberattacks and global DNS failures are much larger in scope than the blackout or brownout incidents, as they cause global infrastructure failure, supply chain disruptions etc. For example, a recent faulty security update from a leading security vendor crippled millions of endpoints and nearly halted thousands of businesses. This incident not only led to lost revenue but also compromised security defenses, making companies vulnerable to a surge of cyberattacks, including spoofed websites, impersonation scams, and malicious ZIP files. Such events demand operational and security resilience that goes beyond simple redundancy, requiring strict isolation, rapid failover, and segmentation to ensure continuous operations and security during widespread crises. 

Zscaler Business Continuity Cloud for critical failures

The questions to ask ourselves is, when the underlying cloud infrastructure or major third-party systems fail at a global scale, should we fail open, and does the security posture vanish with it?

For Zscaler customers, the answer is a definitive no.

Zscaler’s cloud services are already built with high resilience and disaster recovery capabilities including controlling our fate at every level of the stack. Our Business Continuity Cloud provides an added layer with customer-specific backup instances that are physically and logically isolated from the Zero Trust Exchange to maintain operations during critical and larger-scale disruptions.

These events—such as global network outages, infrastructure failures due to cyberattacks, sabotage, or DNS failures—often require specific backup instances beyond the scope of standard service level agreements (SLAs).

Why this matters

In the current geopolitical and environmental climate, "hope" is not a business continuity strategy. The Zscaler Business Continuity Cloud offering provides four critical advantages:

• Operational independence: Isolation from the primary Zero Trust Exchange cloud, providing the required redundancy you need.
• Security integrity: No "failing open"—your zero trust policies remain active even during a global infrastructure crisis.
• Reduced RTO/RPO: Recovery time and point objectives are minimized because the "last known good" state is always ready for immediate failover.
• Consistent end user experience: With a seamless failover from Zscaler Client Connector, users do not have to login again, when they access applications or the internet in business continuity mode.

Building a black-swan-proof enterprise

Incidents affecting regional blackouts, brownouts, or events causing critical failures causing global impact will happen, and true leadership requires preparing for the improbable and the unknown.

Zscaler Business Continuity Cloud isn't just a feature; it’s an insurance policy for the digital age when user experience and security posture must be maintained during events beyond the coverage of standard SLAs. Leveraging Zscaler’s Business Continuity Cloud, you ensure that no matter what happens to the underlying service, your business—and your people—remain protected at all times. 

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Zscaler Resilience Audit

To ensure our customers are prepared for these failure scenarios, while maintaining the appropriate security posture,, Zscaler has developed a continuous framework for assessing the resilience of your Zscaler tenant and configuration maturity. This assessment, conducted by our Technical Success Managers on a periodic basis, also includes the posture of your customer-side configuration and infrastructure. 

This assessment takes into accounts multiple domains:

• Operational Readiness
• Blackout Readiness
• Brownout Readiness
• Business Continuity during Critical Failures

Please contact your account team to get a free assessment of the resilience of your ZIA & ZPA tenants.