On 13 April 2015 a Czech politician planted a flag on an uninhabited bank of the Danube and declared the place the Free Republic of Liberland. By its own account, seven square kilometres of floodplain forest, marsh and scrub between Croatia and Serbia.
It sounds like a stunt with nothing behind it. What makes it interesting is that the legal argument underneath was not pulled out of thin air. The spot is called Gornja Siga, and it really is a special case.
The gap
Croatia and Serbia have disagreed about the course of their Danube border ever since Yugoslavia broke apart. The river has shifted its bed over the centuries. Serbia argues from the present channel, Croatia from the historic cadastral boundaries of the municipalities, which run elsewhere. Both readings are internally consistent, and they produce different maps.
That creates two kinds of land. The first kind each side claims for itself, because its own reading places it inside its own state. The second kind neither side wants, because its own reading hands it to the neighbour. Gornja Siga belongs to the second category. Croatia does not claim it, because on the Croatian reading it would be Serbian. Serbia does not claim it, because on the Serbian reading it would be Croatian. Claiming this patch of woodland would weaken the claimant where the larger and more valuable stretches are at stake.
That is the gap the founder put his flag into. The proclamation was followed, all according to the movement itself, by tens of thousands of citizenship applications, a draft constitution and plans for an economy based on cryptocurrency. On the ground something else followed: Croatia sealed off access repeatedly, and several people were detained while trying to enter, the founder among them. To this day not one state has recognised Liberland.
He was right that nobody wanted the land. He was wrong about what follows from that.
— TerraTally · Borders desk
The error sits in the term terra nullius, land belonging to no one. The concept exists in international law, but it has largely died out there. A floodplain forest that two states decline to claim for tactical reasons is not such a case anyway: it lies inside a border whose course is under negotiation, and in the end it will fall to one of the two sides.
And even if a territory were ownerless, that would create no right for private individuals to found a state on it. Statehood requires territory, a population and an effective government. What decides the matter in practice is whether other states treat you as a counterpart. With Liberland, nobody does. Croatia regards the bank as Croatian-controlled, regardless of who is eventually awarded it, and acts accordingly: with police, not with diplomacy.
That makes Liberland the exact counterpart of the Sovereign Order of Malta. The Order holds no territory and is treated as a subject of international law by more than a hundred states. Liberland holds a piece of land nobody claims and is recognised by no state at all.
Both cases show the same thing. Sovereignty is not a property of soil. It is what others grant you.