“Fortress Country” Concept: protecting critical infrastructure

Updated: 2026 · Reading time: ~6 min

The primary regulatory act that defines how a project corresponds to a specific Engineering Protection Level is CMU Resolution No. 471 dated 26 April 2024 — the “Fortress Country” Concept. Below are the available levels of engineering protection and several of their practical features.

1) Level I (first) of engineering protection under the “Fortress Country” Concept (lowest)

Temporary protective structures intended for initial, partial protection of critical infrastructure elements in case of a single indirect missile hit or indirect UAV hit.

Short‑term (priority) engineering protection measures are intended to reduce the probability of damage to the main elements of critical infrastructure from fragmentation and blast effects of enemy strike means. Such priority organizational and technical measures include: planning the nature and scope of engineering protection based on an analysis of predictive assessments of possible enemy strikes; developing individual or standard engineering solutions for first‑stage structures for critical infrastructure elements; providing the required material and technical resources (including improvised materials) and other resources; constructing engineering structures; operating engineering structures with consideration of the technological requirements of the facility; liquidation of consequences of air strikes and restoration of damaged engineering structures at the facility.

Level I is a basic (minimally sufficient) level used when the first priority is to reduce vulnerability of a building/structure and critical elements of the facility to indirect effects (blast wave, fragments, secondary fragmentation, fire consequences), as well as to ensure a controlled shutdown or rapid restoration of operation. At this level, the correct focus is not “to strengthen everything”, but to identify critical elements (control nodes, power supply, technological lines, reserves, communication channels), understand failure chains and minimize the “domino effect”. Practically this is achieved by a package of solutions: engineering zoning, localization of potential damage, increased fire/industrial resilience and organizational measures (response procedures, access rules, responsible persons, emergency scenarios). It is important that Level I is supported by documentation and embedded into the design: through the civil protection engineering measures section, justification of adopted solutions and control of implementation during construction/repair.

2) Level II (second) of engineering protection under the “Fortress Country” Concept (medium)

Structures that can withstand single direct UAV hits, as well as single indirect missile hits.

The purpose of medium‑term engineering protection measures is to minimize losses from damage to critical infrastructure by constructing above‑ground engineering structures with an increased degree of protection. Medium‑term organizational and technical measures include: design and manufacturing of elements of engineering structures with increased protection degree; provision of required materials and technical resources; construction of such structures; operation at the facility; deceptive measures to mislead the adversary regarding the consequences of air strikes; liquidation of consequences and restoration of damaged structures; control measures aimed at improving second‑stage engineering protection.

Level II is a medium level that implies a significantly more rigorous resilience architecture: in addition to indirect factors, the scenario of a direct UAV impact and indirect missile effects is considered. Here, point strengthening is no longer sufficient — you need a system architecture of resilience: redundancy of key systems, spatial separation of critical functions, enhanced survivability of rooms/control nodes, limitation of fire spread and secondary damage, as well as predictable behavior of structures and technological processes in emergency mode. From a design perspective, Level II almost always means: (1) classification of critical elements; (2) scenario analysis and calculation justifications; (3) an agreed responsibility matrix between the client, designer, contractor and technical supervision; (4) increased requirements for quality control of materials and installation. Separately: part of CI protection materials may fall under restricted information — therefore preparation/transfer of documents and approvals must follow established procedures.

3) Level III (third) of engineering protection under the “Fortress Country” Concept (highest)

Structures intended to protect against a single direct missile and UAV hit.

Achieving reliable protection of critical infrastructure against direct strike means is possible only through long‑term engineering protection measures, by “underground urbanization” and transferring critical elements into recessed protected premises with maximum use of existing development. Long‑term organizational and technical measures include: design of underground engineering structures for protecting CI elements; provision of the necessary materials and resources; construction of underground structures with documentation and accounting of resources; installation of new and relocation of existing technological equipment into protected underground spaces; operation of engineering structures; control measures aimed at improving third‑stage engineering protection.

Level III is the highest level of engineering protection. It applies to facilities and elements whose failure the state/operator cannot allow due to consequences for vital functions, security, the economy or resilience of life‑support systems. Conceptually, this level is focused on counteracting scenarios of direct UAV and missile impacts and implies maximum preservation of functionality or rapid restoration with minimal losses. Key factors for Level III are: complexity (structures + technology + electrical/automation + fire safety + civil protection + operational scenarios), coordination of stakeholders and a seamless bridge between design and construction. In practice, this always means tailor‑made solutions for a specific facility and its critical elements. Errors here are typically not about “thickness” or “material”, but about incorrect criticality assessment, lack of redundancy, uncoordinated interfaces between design disciplines and weak execution control. That is why Level III critically requires professional technical supervision, author’s supervision, design‑to‑as‑built checks and regular update of security passports and protection plans.

4) Mobile shelters and compliance with DSTU

Does not protect against a direct UAV or missile hit. Does not belong to engineering protection levels under the “Fortress Country” Concept.

Primary (mobile) shelters are solutions for short‑term protection of people during a threat period when there are no stationary protective structures or dual‑purpose structures with the required protective properties nearby. For a PRO approach, the key point is: a mobile shelter is not a substitute for a full‑scale shelter or an anti‑radiation shelter, but an instrument for quickly improving personnel safety on a site/territory. In Ukraine, the national standard DSTU 9329:2025 “Primary (mobile) shelters. Main parameters and test methods” defines baseline requirements for such products and allows their civilized use: with parameter verification and a conformity assessment procedure. If a mobile shelter is installed at a critical infrastructure facility, it must be integrated into the protection system: capacity and use scenarios defined, accessibility and safe route ensured, operation/inspection rules in place, and reflected in the protection plan and civil protection documentation. Otherwise, even an expensive unit will not deliver the expected effect.

5) Anti‑radiation shelter (ARS/ПРУ) and compliance with DBN

Does not protect against a direct UAV or missile hit. Does not belong to engineering protection levels under the “Fortress Country” Concept.

Anti‑radiation shelters (ARS / ПРУ) are one type of civil protection protective structures. Their purpose is to provide shelter for people from hazardous factors, including during a special period, within the requirements of current legislation and building codes. In terms of design requirements for creation/reconstruction of ARS and dual‑purpose structures, key provisions are defined, in particular, by DBN V.2.2‑5:2023 “Civil protection protective structures”.

For the client, it is important to understand: an ARS is not “any basement”. It is an engineered facility with a defined functional purpose, requirements for solutions, engineering systems and operation. In the design documentation, such solutions must be properly reflected in the civil protection engineering measures section, and during implementation — confirmed by quality control and design‑to‑as‑built compliance. For critical infrastructure, an ARS (or a dual‑purpose structure with ARS protective properties) is essentially a baseline element of the “human safety loop”: it reduces risks for personnel and increases operational resilience of the facility during threats.