The Practical Prerequisites for Achieving a Just and Lasting Peace: Ukraine's Red Lines

Key Chapter Title List

1. What Ukraine's Red Lines Are and Are Not
2. Lessons from the Minsk Agreements: The Flaws of Agreements Lacking Enforcement Mechanisms
3. Domestic Legitimacy Constraints: Public Consensus on Minimum Security Requirements
4. The Core Red Line: Defense Capability Not Below Effective Self-Defense Capacity
5. The Distinction Between Troop Ceilings and Force Structure: Sovereign Flexibility and Sustainability
6. The Deterrence Perspective: The Stabilizing Role of Sufficient Defensive Capability
7. Structural Dilemmas in Contemporary Armed Conflict: The Asymmetry Between Legitimate Restraint and Illegal Coercion
8. Structural Choices and Defensive Architecture Requirements in Future Conflicts

Document Introduction

This report, published by the Center for Transatlantic Dialogue, aims to clarify widespread misconceptions regarding the concept of Ukraine's red lines in potential peace negotiations. The report explicitly states that Ukraine's red lines are not negotiating postures aimed at extracting concessions, but rather security thresholds concerning national survival. They define the minimum conditions under which Ukraine can continue to exist as a sovereign actor, deter renewed aggression, and exercise independent political choice. The roots of this concept lie in Ukraine's experience since 2014, where de-escalation periods lacking credible enforcement mechanisms failed to bring stability, ultimately leading to the full-scale invasion in 2022.

The report first analyzes the failure of the Minsk Agreements framework, pointing out that while they provided monitoring, they lacked credible attribution, accountability, and enforcement mechanisms, failing to prevent repeated violations of ceasefire terms by Russia and its proxies. Based on this, Kyiv's core operational lesson is that security arrangements that allow for the degradation of defense capabilities or rely on unenforced commitments create incentives for new aggression. The report further reveals, through public opinion poll data from 2024-2025, the strong domestic legitimacy constraints in Ukraine. The data shows that an overwhelming majority of Ukrainians oppose significant reductions in defense capabilities, accepting vague security guarantees, or de facto recognition of territorial losses. This consensus remains solid even against the backdrop of increasing war fatigue, indicating that willingness to negotiate does not equate to accepting structural vulnerability.

The core section of the report elaborates in detail on Ukraine's primary red line: retaining effective self-defense capability. Any externally imposed troop ceilings or demilitarization clauses that substantially weaken Ukraine's ability to deter renewed aggression are unacceptable. Using the troop ceiling issue involved in the November 2025 negotiation draft as an example, the report notes that Ukraine insists on a ceiling of approximately 800,000 personnel. This roughly corresponds to the effective force level currently required to maintain multi-directional defense and is seen as the minimum deterrence threshold. The report particularly emphasizes the crucial distinction between troop ceilings and force structure: Ukraine needs a higher statutory ceiling to ensure sovereign flexibility (i.e., legal elasticity) in response to Russian probing actions; while the actual force structure will be scaled down to a more sustainable, professional core, supplemented by well-trained reserves, territorial defense forces, and mobilization infrastructure.

From the perspective of deterrence theory, the report argues that maintaining sufficient defensive capability is a stabilizing, not an escalatory, factor, consistent with the logic of NATO's force deployments on its eastern flank. Finally, the report points to a deeper structural dilemma: the persistent asymmetry between legitimate restraint and illegal coercion in the absence of credible international humanitarian law enforcement mechanisms. Russia systematically targets civilians and critical infrastructure as a means of coercion, while Ukraine must simultaneously engage in strategic overstretch between frontline defense, protecting civilians in the deep rear, and maintaining counter-offensive capability. Facing future conflicts, Ukraine must construct a defensive architecture capable of both resisting advanced missile threats and intercepting large quantities of low-cost attack systems at low cost, while also protecting civilian infrastructure. This inevitably demands corresponding personnel, resource, and institutional depth. Without these capabilities, this asymmetry will continue to favor the aggressor.