Secretary of State John Kerry spent the spring shuttling between his two major foreign-policy concerns—Russia’s control over Crimea and Israel’s control over the West Bank—entirely unaware that he was engaged in a world-historical irony. Both these situations turn on identical international-law principles. Indeed, the failure of the United States to apply these principles consistently has led to the long-standing failure of its Middle East initiatives, while inadvertently opening the door for Russian aggression.

The legal principle that explains why Crimea was and remains under Ukraine’s sovereignty also validates Israel’s presence in the West Bank.

Let us start with the less controversial case. The international community agrees that, despite Russia’s annexation, Crimea remains sovereign Ukrainian territory. On March 27, the UN General Assembly voted 100 to 11 to continue to recognize Crimea as part of Ukraine. Russia cannot rewrite Ukraine’s frontiers at will.

But, as many foreign-policy realists argued while Vladimir Putin was making his move, it is not all that clear why Crimea should belong to Ukraine in the first place. The substantial majority of the population is ethnically, linguistically, and religiously Russian. The majority of its population probably prefers to be ruled from Moscow rather than Kiev (though not by the 90-plus percent margin of the recent shotgun referendum). The territory is adjacent to Russia and has been part of Russia historically.

So why Ukrainian sovereignty over Crimea? The answer: Nikita Khrushchev’s caprice. In 1954, the first secretary of the Central Committee detached Crimea from the Russian Soviet Socialist Republic and gave it to the Ukrainian Soviet Socialist Republic. He did not consult the Crimeans, but it did not much matter, as everyone was ruled from the Kremlin anyway. From that moment on, official internal Soviet borders included Crimea in Ukraine.

Thus, all Ukraine has for its claim of title to Crimea is a dead dictator’s whim. But for international law, that is more than enough. When new countries emerge from old ones or from colonial empires, the last official international borders constitute the new boundary lines. This doctrine is known as uti possidetis iuris (meaning “you possess under law”). It has been applied to the borders of new states around the world and recognized as a basic principle of international law by the International Court of Justice. Even when several states emerge from one, as Russia and Ukraine did from the USSR, the prior internal administrative divisions become the new international frontiers.

Most striking, this principle applies in full when the old borders were colonial or otherwise undemocratically imposed. If it were not so, new countries would be born with all their borders in dispute, and endless frontier conflicts between neighbors would ensue. That is why international law sets the last official boundaries, even colonial provincial boundaries, as the permanent ones. Subsequent aggression cannot change them, as the reaction to Russia’s Crimean conquest shows.

Now let us apply these principles to Israel.

The disintegration of the Ottoman Empire in World War I led to the division of its territories in the Middle East. The core of the Ottoman Empire became the new country of Turkey, which, in turn, surrendered all Turkish sovereignty over Ottoman territory in the rest of the Middle East (not just Israel, but also modern-day Iraq, Syria, Lebanon, and Jordan). Instead of imposing their own sovereignty on the parts of the Ottoman Empire they conquered, Britain and France allowed the newly created League of Nations to transform these territories into “mandates.” The European states were committed to shepherding the mandates into new independent nation-states. The League did so pursuant to an explicit clause in its charter that authorized it to create such mandates out of the lands “formerly belonging to the Turkish Empire.”

In 1922, the League of Nations established a new “country” to serve as the Jewish national home. This was the Mandate for Palestine. Under certain provisions of the Mandate, Palestine was partitioned at the Jordan River to create the country of Transjordan (now called Jordan) on its eastern bank. After that, international frontiers of Mandatory Palestine ran from the river to the sea. The League of Nations Mandate for Palestine provides the legal basis not only for Israel’s borders, but for those of Jordan as well, and indeed for Jordan’s entire existence.

Israel is the state created in Mandatory Palestine. Thus under uti possidetis iuris, it inherits the Mandatory borders. The only question is whether anything has happened since the 1920s that legally modified these frontiers.

Three events are commonly cited as justifying the non-application of the uti possidetis doctrine. First was the UN General Assembly’s 1947 partition proposal, Resolution 181. Second was the partially successful 1948–49 Arab attempt to prevent the establishment of a Jewish state in Palestine, which led to the Green Line of 1949. Third was the UN Security Council’s response to Israel’s retaking of these territories in the Six-Day War.

The Partition Proposal

 Resolution 181 did not, as many seem to think, “create” the Jewish state. That had been done on paper 25 years earlier by the League of Nations Mandate, and later through Israel’s declaration of independence and War of Independence—a struggle in which the UN did nothing to promote the survival of the fledgling state.

Resolution 181 proposed an elaborate seven-sector division of Mandatory Palestine, an idea the Jewish leadership was willing to accept, but that the Arabs rejected. The General Assembly Resolution did nothing to alter the Mandatory borders because the GA is not a world legislature: It has no legal power to make any binding rules, let alone redraw the borders of nations.

Indeed, the resolution itself explicitly recognizes that the Assembly has no power to legislate its recommendations. If the GA were to vote today to “partition” Ukraine, it would be similarly ineffectual. The 1947 plan was a proposal for a compromise that, if accepted by both sides, would have been binding, but which had no force in itself.

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