Achieving Digital Sovereignty in Defence cloud: a practical guide 

This blog was written by Dan Jones, Defence Account Manager, 4Secure

A strategic guide exists for implementing digital sovereignty in defence cloud systems. However, the UK defence currently operates in the cloud environment without any ongoing discussion about its use. If digital sovereignty is the key, then ongoing discussion and improvement is crucial. This process will lead to the desired state of implementing cloud technologies which preserve complete control over data management and operational decision-making capabilities.

The right implementation will enable operational agility along with resilience and trust, but incorrect implementation will limit or endanger critical capabilities. This blog is designed to complement the UK cloud strategic roadmap for Defence and delivers operational guidance to achieve defence digital sovereignty through essential components and warning signs along with defence strategy alignment.

1. Start with a sovereignty map 

All cloud deployments must go through a data estate mapping process before actual deployment. A structured sovereignty map helps organisations detect possible risks at their initial stages. The process enables you to establish service-level agreements and technical parameters with providers that fulfil UK defence specifications.

Points of Consideration:

Create records that show the storage and processing and backup locations for all data.
Every location needs identification of jurisdictions which hold legal power and identification of relevant regulations.
The sovereignty assessment requires full examination of both primary datasets and metadata together with logs and backups since they contain equal sensitivity levels.

2. Establishing Jurisdictional Boundaries in Data Sovereignty

Data sovereignty demands that all sensitive data remains under complete legal control of a single defined jurisdiction. The lack of defined jurisdictional boundaries creates major legal risks and foreign interference threats for organisations as shown by the US CLOUD Act which enables US authorities to access data from US-owned companies regardless of storage location thus exposing UK-based data centres to foreign jurisdiction when operated by overseas owners.

Points Of Consideration:

All sensitive workloads must operate exclusively under UK jurisdiction within domestic legal structures
Storage, processing, and management functions require complete separation from foreign legal frameworks
Physical location alone is insufficient - ownership and operational control determine jurisdictional authority
Clear protocols must establish who can legitimately request data access and under what circumstances
Due diligence on data centre ownership is essential to prevent inadvertent foreign jurisdiction exposure

3. Build in Cross Domain Solutions (CDS) from day one 

The secure exchange of data between classification levels in defence information systems depends on Cross Domain Solutions (CDS) which function as policy-controlled gateways that enforce access permissions and data transformation rules while providing complete monitoring across different security domains. The implementation of CDS solutions after cloud design completion leads to significant security risks and operational delays because of architectural mismatches which force costly redesigns and expose system vulnerabilities thus organisations must decide between maintaining security boundaries and achieving operational agility unless CDS integration occurs during the initial design phase.

Points of Consideration:

System developers should incorporate CDS architecture into their first design phases before considering it as an optional feature.
The system must have secure gateways which manage information exchange across security classification levels.
The system needs to establish complete access rules and data modification procedures at the start.
A monitoring system should be built to track and audit all cross-domain data exchanges.
CDS policies need to match both security requirements and operational agility needs for proper implementation.
System design should anticipate scalability requirements for security domains as well as data volume expansion.

4. Make Information Assurance a continuous process 

The modern defence environment needs ongoing security assessments instead of fixed evaluations because threats and operational needs evolve constantly while Information Assurance depends on permanent processes that security accreditation functions as a crucial yet short-term assessment tool. The requirement for digital sovereignty needs organisations to verify security measures protecting sensitive data throughout their system's operational lifecycle because outdated security postures that have weakened since the last formal evaluation create organisational risks. The MOD Security Policy Framework, Risk Management Framework and GovAssure provide structural guidance, but these frameworks achieve success only when organisations maintain a culture of continuous security dedication instead of performing basic compliance checks.

Points Of Consideration:

Security performance needs to be monitored through continuous systems that provide real-time tracking
Regular penetration testing needs to be performed to detect new system vulnerabilities and weaknesses that emerge.
System resilience and response capabilities should be tested through active incident simulation exercises.
Operational cycles should integrate assurance activities instead of treating them as periodic events.
Leadership needs to demonstrate ongoing security dedication instead of treating it as a compliance requirement.
The continuous assurance processes need to follow MOD frameworks yet maintain operational adaptability.
The assurance process needs to establish feedback mechanisms which convert findings into immediate security enhancements

5. Plan for supply chain sovereignty 

Data sovereignty reaches beyond organisational boundaries to include the entire supply chain ecosystem because an organisation's security position depends on the sovereignty posture of all subcontractors, partners, and suppliers who access sensitive workloads, since they represent potential points of jurisdictional vulnerability.

The strength of sovereignty depends on the weakest link in the supply chain because technologically secure systems become exposed to threats when suppliers operate under foreign laws or lack sufficient contractual safeguards which makes all internal sovereignty measures vulnerable to legal and strategic exposure through inadequate third-party relationship controls.

Points Of Consideration:

All subcontractors who handle sensitive workloads must operate exclusively under UK jurisdiction
All supplier contracts must contain explicit jurisdictional requirements and compliance obligations
The organisation must establish detailed audit rights to check supplier sovereignty measures and their ongoing compliance status
The organisation should perform routine supply chain risk assessments to detect potential jurisdictional weaknesses.
The organisation should establish contractual mechanisms which enable the enforcement of supplier security practices.
The organisation must develop emergency response plans for situations where suppliers fail to comply or change their jurisdiction.
Supply chain sovereignty requirements need to extend through multiple levels of subcontractors.

6. Align With Wider Defence Strategy 

Sovereign systems allow strategic collaboration through UK defence operations by implementing sovereignty to achieve security restrictions and operational requirements of coalition warfare and alliance partnerships, where true sovereignty requires complete system and data control while enabling secure interoperability with trusted partners when collaboration becomes necessary for mission requirements.

Systems that operate independently without safe alliance interaction capabilities create operational challenges that damage both defence effectiveness and strategic relationships, while unregulated data exchange violates national sovereignty by revealing sensitive information to foreign legal systems, making the main difficulty the development of systems that fulfil operational readiness and innovation requirements through strict data sharing controls regarding timing and recipient organisations.

Points of Consideration:

Design sovereign systems with built-in secure interoperability capabilities for alliance operations
The system should have defined procedures which determine how trusted coalition partners can access data
The system should have multiple levels of access authorization to allow joint work without compromising essential sovereignty rights
The system should have secure methods to exchange information in real time when performing joint operations
The organisation should establish specific guidelines to determine both the operational necessity and authorized entities for data sharing
The systems should develop operational readiness and capability deployment capabilities for alliance structures.
The interoperability features should boost overall sovereignty position instead of diminishing it.
The design of collaboration tools should support innovation through secure boundaries.

The benefits of doing it right 

When sovereignty is designed into your cloud approach, the benefits extend beyond security: 

Operational independence - the ability to act without waiting for external approval. 
Reduced legal and compliance exposure - full alignment with UK law. 
Higher partner confidence - demonstrating assured control builds trust with allies. 
Faster accreditation - sovereign-by-design systems move more quickly through approval processes. 
Improved resilience - sovereign systems can be adapted and scaled without dependency on foreign policy or infrastructure changes.

Digital sovereignty in defence is not just a single procurement decision. It is an ongoing commitment to control, assurance, and resilience, which is built into every design choice and operational process. Those who take this approach will not only protect their data but also strengthen their operational freedom and strategic credibility. 