This Article provides the first comprehensive, global examination of state and international practice bearing on Article 49(6) of the Fourth Geneva Convention, which provides that an “Occupying Power shall not deport or transfer parts of its own civilian population into the territory it occupies.” This provision is a staple of legal and diplomatic international discussions of the Arab-Israeli conflict, and serves as the basis for criticism of Israeli settlement policy.

Despite its frequent invocation in the Israeli context, scholars have never examined – or even considered – how the norm has been interpreted and applied in any other occupation context in the post-WWII era. For example, the International Committee of the Red Cross’s (ICRC) influential S tudy on Customary International Humanitarian Law lists 107 instances of national practice and UN practice applying or interpreting the prohibition, and all but two relate to Israel. Many questions exist about the scope and application of Art. 49(6)’s prohibition on “transfer,” but they have generally been answered on purely theoretically.

To better understand what Art. 49(6) does in fact demand, this Article closely examines its application in all other cases in which it could apply. Many of the settlement enterprises studied in this Article have never been discussed or documented. All of these situations involved the movement of settlers into the occupied territory, in numbers ranging from thousands to hundreds of thousands. Indeed, perhaps every prolonged occupation of contiguous habitable territory has resulted in significant settlement activity.

Clear patterns emerge from this systematic study of state practice. Strikingly, the state practice paints a picture that is significantly inconsistent with the prior conventional wisdom concerning Art. 49(6). First, the migration of people into occupied territory is a near-ubiquitous feature of extended belligerent occupations. Second, no occupying power has ever taken any measures to discourage or prevent such settlement activity, nor has any occupying power ever expressed opinio juris suggesting that it is bound to do so. Third, and perhaps most strikingly, in none of these situations have the international community or international organizations described the migration of persons into the occupied territory as a violation of Art. 49(6). Even in the rare cases in which such policies have met with international criticism, it has not been in legal terms. This suggests that the level of direct state involvement in “transfer” required to constitute an Art. 49(6) violation may be significantly greater than previously thought. Finally, neither international political bodies nor the new governments of previously occupied territories have ever embraced the removal of illegally transferred civilian settlers as an appropriate remedy.

The deeper understanding – based on a systematic survey of all available state practice – of the prohibition on settlements should inform legal discussions of the Arab-Israeli- conflict, including potential investigations into such activity by the International Criminal Court. More broadly, the new understanding of Art. 49(6) developed here can also shed significant light on the proper treatment of several ongoing occupations, from Western Sahara and Northern Cyprus, to the Russian occupations of Ukraine and Georgia, whose settlement policies this Article is the first to document.