Russia last week held a referendum on whether the occupied regions of Ukraine would want to join Russia. Many states and international institutions have already made clear that they will not accept the result, because it seems obvious that the outcome will be faked and people are not free in their decision.

Therefore my question: What would be a legal way of achieving this? Are there any international laws on that, or does it depend mostly on the laws of the countries involved? I do know that there have been some polls about regions changing state in the past (e.g. the 1919 poll in Vorarlberg), but I don't know of a recent one and I don't know of any successful ones.

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    Two examples that might be of interest to you. The unification of Southern Jutland with Denmark in 1920 and the peaceful dissolution of Czechoslovakia in 1992. In the case of the Denmark, the Versailles treaty specified that there had to be a vote with every county voting for Denmark or Germany. The final border was established by the Danish-German treaty of 1922. The Copenhagen-Bonn declarations of 1955 have been integrated into national law by both countries ensuring that the rights of the minorities are respected on either side of the border. Sep 27, 2022 at 22:06
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    @CarlChristian And with the Czechoslovakia, the relevant is the (agreed by both parties) transfer of the village U Sabotů from the Czech Republic to Slovakia (because of an inconveniently placed railway), much to the displeasure of the inhabitants that was not taken into account (and that was before Slovakia went into the troubles full swing) Sep 29, 2022 at 8:10

4 Answers 4


So generally, when a region of a nation tries to break away and form a new nation or join a nation, it's acceptance as a nation is generally based on the Diplomatic Recognition of other Nations. This can either be de facto or de jure, with the former acting in a manner of having some acknowledgement of a government of a territory, while a de jure recognition typically is stronger with embassies, consulates, and treaties between the two nations. For example, the United States has de jure recognition of France and vice versa, while they merely have de facto recognition with Iran (They recognize there is a government of the territorial area known as Iran, but they feel that the current government is illegitimate and refuse to engage with it in diplomatic relationships. Iran similarly knows there is a United States, but refuses to recognize it for political reasons as well.). When two nations do not have de jure recognition they will often appoint another nation "Protecting Power" who will act as a representative of the appointing nation in the nation they do not recognize. Currently, the Swiss Embassy in Iran has an office dedicated to U.S. affairs as it is the Protecting Power of the United States in Iran. Iran has asked Pakistan to have the same duties. And before you ask, yes, it is the geopolitical equivalent of two people in the same room not speaking to one another, but telling a third person to give the other person a message (U.S.: Switzerland tell Iran that they will give us back our citizens who are being held in their jail cells or we will drop bombs on them. Switzerland: rolls eyes Iran, the U.S. says they want their guys back or they will bomb you. Iran: Oh yeah? Tell U.S. 'Death to America!' Switzerland: eye roll They said... U.S.: Already routing the bombers!)

If a region is claimed by more than one government, than it becomes disputed territory. Presently China has a lot of disputed territory with its neighbors and Maritime neighbors. Ongoing disputes include territories also claimed by India, Bhutan, Japan, Taiwan, Vietnam, Malaysia, and The Philippines. Interestingly, the dispute with Taiwan is over who is the real government of China... Taiwan claims much of the other disputed territory China does... plus some territories which China has resolved disputes over.

The Russia-Ukraine situation will likely leave the territory in question (The Donbas and Crimea Regions) listed as disputed. Generally, disputed territory doesn't mean nations cannot be friendly, as the United States has a number of territorial disputes with Canada, despite being very strong diplomatic allies (with the single largest land boarder between two nations in the world, disputed territory was bound to happen). Perhaps the most interesting is the now resolved dispute of the San Juan Island in Washington State. Oversimplified History has a good video about it on his YouTube channel, specifically the "Pig War" confrontations and does a pretty good job of highlighting just how dramatic the change to the modern border would have been.

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    It's worth noting that none of the US/Canada disputes involve inhabited land: en.wikipedia.org/wiki/…
    – Flydog57
    Sep 28, 2022 at 15:25
  • @Flydog57: Do you mean uninhabited?
    – hszmv
    Sep 28, 2022 at 15:34
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    Sorry, a not-quite double negative: "that none of the disputes involve inhabited land"
    – Flydog57
    Sep 28, 2022 at 16:02
  • I'm not sure whether considering a nation's government illegitimate implies denying the existence of the nation. The other way around the argument holds, of course. I would think that the U.S. government (and the rest of the world) operates under the notion of a nation "Iran". Sep 28, 2022 at 22:44
  • @Peter-ReinstateMonica: It does not. Consider the nation of Venezuela, which currently has dispute of who is really in charge of the nation following the 2018 elections. The U.S. (and several other nations) consider the Juan Guaidó the President of Venezuela, while other nations sided with Incumbent Nicolás Maduro, who has yet to transition power to the U.S. supported leadership. Thus the current Maduro government is illegit. Contrast that with the Government of Palestine, which is not recognized by the United States (and others) because they don't recognize Palestine as a nation at all.
    – hszmv
    Sep 29, 2022 at 14:56

What would be a legal way of achieving this?

The meaning of "legal" at international scale is whimsical. What people usually refer to as "international laws" are not, strictly speaking (and can't be) laws as such. Rather, they are just treaties, agreements, conventions etc. between certain countries (sovereign states). Some participate in those treaties, some don't. Some are more or less consistent in their attitude, other would sway depending on their current political agenda.

Hence, if a country doesn't participate in any of those treaties, there is no basis to accuse it of breaking "international laws". Whatever it does outside its borders becomes a matter of geopolitics, not law.

Now, "the change of country of a region" may be considered "lawful" from the point of view of those countries that participate in international treaties, but only in a scenario like this:

  1. The region itself declares independence and gets diplomatic recognition. Importantly, this separation must be genuinely driven from inside the region by its residents, not pushed or orchestrated from outside.
  2. The region itself requests to become a part of another country. Again, this must be driven by the region's own residents, and not in any way orchestrated (let alone forced) by the would-be new home country.
  • Some customary international law is deemed by the international community to have become jus cogens. Opinions about the exact list differs, but the concept is accepted.
    – o.m.
    Sep 29, 2022 at 10:31
  • @o.m. jus cogens is still free to be accepted or rejected by sovereign states. The fact that the majority accepts it creates only political pressure over the minority that doesn't, not jurisdiction.
    – Greendrake
    Sep 29, 2022 at 11:29
  • Depends on how upset the other countries are. Blatant violation may lead to enforcement actions.
    – o.m.
    Sep 29, 2022 at 14:22
  • @o.m. Sure it may. But that use of force would still be geopolitical, not jurisdictional. Pretty much like any invasion of one sovereign state into another, no matter what the reasons are.
    – Greendrake
    Sep 29, 2022 at 14:43

Legally, territory transfer should be the subject of a treaty between the two countries concerned, duly ratified by each country according to its constitutional requirements. In recent decades (or centuries?) there has been increasing attention paid to the right of self determination, so a referendum showing that a majority of the population is in favor would be desirable politically. I'm not aware of any existing treaty that would require this or that otherwise describes any mechanism for determining the will of the people. A treaty concerning such a transfer could contain such a requirement; if I recall correctly the Good Friday agreement is an example of such a treaty, but of course this provision of the treaty has not been invoked.

Without doing any research, I can think of one such transfer (without any population), which is the adjustment of the border between France and Switzerland in connection with construction of the Geneva airport. Like you, I am unaware of a transfer of populated territory that wasn't brought about by a war.

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    Maybe the sale of Alaska might be considered such a transfer. At the time of it, Alaska wasn't considered part of a state, tough. And of course, the population didn't have a vote on it.
    – PMF
    Sep 27, 2022 at 11:46
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    @PMF yes, that's a good example. It does get a bit murky when you start talking about colonies and territories and so on.
    – phoog
    Sep 27, 2022 at 11:48
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    There have been several cases of peaceful territory transfers, most notably the India-Bangladesh enclave transfers. Sep 27, 2022 at 23:47
  • @curiousdannii and territory swaps are going on all the time (typical reason: the border follows the old river, the river changed course and left a piece of otherwise inaccessible land on the other side), usually the same area (so that nobody can protest) and without population; this is not even worth reporting in mass media Sep 29, 2022 at 10:19

The only legal way is for both countries claiming that territory to agree on who owns what. There is no other mechanism. In particular, self-determination of people within that area is not a factor.

The situation of the Golan Heights is similar. In that case, an invading army first occupied an area of another country and then fully annexed it. Under international law this area still belongs to Syria, in spite of the fact that it has been under full Israeli control for decades. (The fact of Israel initially occupying this area for strategic military reasons after being attacked by Syria is not relevant legally.)

It's worth noting that the land border of Ukraine was previously well-established as the border of what was a well-defined area of the USSR. (Ownership of islands may have been in dispute, but the land border was not.) At the time, the people of Crimea were significantly opposed to becoming part of Ukraine, but this did not affect the status of Crimea as being part of Ukraine. It may also be worth noting too that Crimea's inclusion as part of Ukraine was itself imposed by USSR central government, without consideration of Crimea's citizens.

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