Its expropriation procedure was unique. Until 1979, settlements were established on land requisitioned by military order claiming these communities would serve an important security function. Three times, Israel's High Court concurred until it held (in 1979) that the Elon Moreh order was illegal because it failed to meet that definition.
Thereafter, declarations arbitrarily classified over 90,000 West Bank hectares as state land, most of it later included within the jurisdictional boundaries of local and regional settlement councils. The major Ma'ale Adummim expropriations occurred in 1975 and 1977 for military needs, before the Elon Moreh ruling.
"The difference between the two procedures relates to their validity over time." Land requisition is temporary, but may be repeatedly extended. It doesn't change ownership, just the temporary right to use it. Payment is also offered, so, in fact, the landowner is forced to "lease" the land to the state.
In contrast, expropriation is permanent, switching ownership from Palestinians to the state against the owner's will, even though payment is offered that may be refused and often is to make a political statement.
Israel expropriated land for Ma'ale Adummim to make it an integral part of Jerusalem. Shortly after the 1967 war, the government annexed West Bank land to expand the city's borders for demographic reasons, "a mere" 7,000 hectares to avoid an adverse international reaction. The order included large areas to the east and south to ensure Israeli control of a strategic location, controlling passage between the northern and southern parts of the West Bank to Jerusalem, Jordan and Jericho.
The development planned residential neighborhoods and an industrial zone with more land expropriated than needed for future use and to make Ma'ale Adummim a Jerusalem suburb.
In 1977, the Likud government recognized two former "work camps" as civilian communities, Ma'ale Adummim and Ofra. The latter set a precedent as an "unauthorized outpost." As the first northern West Bank settlement, it broke "the barrier that blocked settlement attempts in the heart of the Palestinian population" and established events on the ground for dozens more to follow - illegal settlements and outposts "in opposition to the stated official position of the government," only on paper to be ignored.
Prior to the Elon Moreh ruling, the Israeli High Court held that expropriating Occupied Territory private property for a security or civilian settlement was prohibited under international law (the Hague Convention), while temporary requisitioning was legal.