More than four years on, the war in Ukraine has settled into something the early headlines did not anticipate: a grinding, attritional conflict with no clean end in sight. Behind the front lines runs a second contest, quieter but no less consequential — a contest over law. Sovereignty, the use of force, the treatment of civilians, and the fate of hundreds of billions in frozen assets are all being argued in legal terms. This is an attempt to map that architecture, neutrally and without taking sides.
It is, by most estimates, the largest armed conflict on European soil since the Second World War. The human cost is difficult to state with precision, and credible figures are contested, but the broad picture reported by international agencies is sobering: many thousands of civilians killed and injured, vast damage to homes and infrastructure, and — as of early 2026 — millions of Ukrainians displaced both within the country and as refugees abroad. Whatever one's view of the conflict's origins, the scale of disruption to civilian life is not seriously disputed.
What follows is not a political verdict. It is a guide to the legal vocabulary through which states, courts, and institutions are framing the conflict — and to the questions that remain genuinely unresolved.
A conflict of continental scale
The first thing to grasp is magnitude. Independent monitors and humanitarian bodies describe a displacement crisis of a size Europe has not seen in generations, with reportedly millions of people uprooted and large urban areas damaged or destroyed. Energy grids, hospitals, and water systems have been repeatedly affected, with knock-on effects for civilian survival through successive winters.
The economic ripples extend well beyond the region. Disruption to grain and fertiliser exports, energy markets, and supply chains has, by most estimates, affected food security and prices in countries far removed from the fighting. For lawyers, this scale matters: the larger and more protracted a conflict, the more legal regimes it engages — humanitarian law, refugee law, sanctions law, and the law governing reconstruction and reparations all come into play at once.
International law does not stop a war; it frames how the world judges it. The rules on force, on the conduct of hostilities, and on accountability continue to apply whether or not the parties observe them — and they shape what comes after the fighting ends.
The law on the use of force
At the centre of the legal debate sits the United Nations Charter. Article 2(4) requires member states to refrain "from the threat or use of force against the territorial integrity or political independence of any state." The recognised exceptions are narrow: self-defence under Article 51, and action authorised by the UN Security Council. Sovereignty and territorial integrity are foundational principles of the post-1945 order, and most states treat the inviolability of recognised borders as a cornerstone of international stability.
Ukraine and many states argue that the conflict represents a clear breach of Article 2(4) and an act of aggression. Russia maintains that its actions are justified on security and self-defence grounds. The UN General Assembly has, in resolutions reported since 2022, expressed positions on the conflict, though such resolutions are not in themselves legally binding. The "crime of aggression" — the leadership crime of planning or waging a manifestly unlawful war — is a distinct concept in international criminal law, and the question of which body could lawfully try it is itself contested, as discussed below.
Several of the most significant issues remain genuinely unresolved as a matter of law and procedure:
- Through which forum, if any, could the crime of aggression be prosecuted against the most senior leadership?
- What is the lawful basis, if one exists, for transferring frozen sovereign assets to fund reconstruction?
- How is state immunity reconciled with claims for reparations arising from an unlawful use of force?
- How are humanitarian-law obligations enforced against parties that decline to cooperate with international courts?
- What weight do non-binding General Assembly resolutions carry in shaping customary international law over time?
The law in the fighting
Separate from the question of whether the war is lawful is the question of how it is fought. International humanitarian law (IHL) — chiefly the Geneva Conventions and their Additional Protocols — applies to all parties to an armed conflict regardless of who is considered the aggressor. Its core principles are distinction (between combatants and civilians), proportionality, and precaution. Attacks directed at civilians or civilian objects, and indiscriminate attacks, are prohibited.
Numerous alleged violations have been reported by international bodies, including attacks affecting civilian areas, treatment of prisoners, and the reported transfer of children. These are allegations and, where pursued, must be established through proper process. The International Criminal Court has issued arrest warrants in connection with the conflict; such warrants are accusatory instruments, not findings of guilt, and the Court's jurisdiction and the prospects of enforcement remain contested. Russia is not a party to the Rome Statute and rejects the Court's jurisdiction over its nationals.
Beyond the ICC, several accountability mechanisms have been reported: national prosecutions in Ukraine and in third states under universal-jurisdiction principles, international commissions of inquiry, and evidence-preservation efforts. A persistent debate concerns whether a dedicated special tribunal on the crime of aggression should be established — Ukraine and a number of states argue such a tribunal is necessary to reach the leadership crime that the ICC may be unable to prosecute, while others raise questions about its legal basis, legitimacy, and selectivity.
Frozen assets and the reparations question
One of the most legally novel debates concerns money. Following the escalation of the conflict, a substantial volume of Russian sovereign assets — reportedly around US$300bn in central-bank reserves — was immobilised in jurisdictions across Europe, North America, and elsewhere. Immobilising assets, which freezes them in place, is widely regarded as lawful under existing sanctions powers. Confiscating them outright, and redirecting them to Ukrainian reconstruction, raises far harder questions.
Proponents argue that a state responsible for an unlawful war should bear the cost of the damage it causes, and that countermeasures or new legal instruments could justify transfer. Critics caution that state immunity, the protection of central-bank assets, property-rights guarantees, and the risk to confidence in the international financial system all weigh against outright seizure. Several governments have explored intermediate approaches, such as directing the profits or windfall income generated by immobilised assets toward Ukraine rather than confiscating the principal — an attempt to reconcile competing legal concerns.
Running alongside this is the machinery of reparations. A Register of Damage has been established to record claims arising from the conflict, conceived as a first step toward a future compensation mechanism. How such a mechanism would be funded, and how it would interact with the frozen-asset debate and with principles of state responsibility, remains, as of early 2026, an open and actively contested question.
- By most estimates the largest war in Europe since 1945, with millions reportedly displaced and a human and economic toll felt far beyond the region.
- The UN Charter's Article 2(4) prohibition on the use of force, and the principles of sovereignty and territorial integrity, sit at the centre of the legal debate — with the parties advancing opposing arguments.
- Humanitarian law binds all parties regardless of who is the aggressor; alleged violations and ICC arrest warrants are accusatory, not findings of guilt, and enforcement remains contested.
- Roughly US$300bn in Russian sovereign assets has reportedly been immobilised abroad; freezing is broadly accepted, but outright confiscation for reconstruction raises unresolved legal questions.
- A Register of Damage and the prospect of a special tribunal on aggression illustrate that accountability and reparations remain works in progress.
How Crejj & Partners can help
We are commentators on these questions, not parties to the conflict, and we offer no political position on it. Where the war touches the practical concerns of our clients, however, our team can assist: advising businesses and individuals on sanctions compliance and the shifting designations that accompany a conflict of this scale; helping clients understand frozen-asset, banking, and cross-border exposure; and, in appropriate cases, advising on civil recovery and the preservation of evidence for claims that may one day be pursued. Our role is modest and honest — to help clients navigate the legal consequences of an unstable world, not to litigate its rights and wrongs. If your affairs intersect with these issues, we are glad to talk them through.
This article is provided for general information and analysis only. It is not legal advice, does not constitute political endorsement of any party, and does not create a solicitor–client relationship. Descriptions of an ongoing conflict reflect publicly reported information as of mid-2026 and may since have changed. Crejj & Partners is a fictional firm presented for illustrative purposes on this website.