While it’s unclear exactly how this plan was supposed to work, or if the U.S. was hoping to enact it unilaterally or in cooperation with Mexico, it is a policy that has plenty of precedents. Since the 1970s, the U.S. has employed similar measures for several different countries, including Vietnam, Haiti, Iraq, and some Central American states. More recently, Australia has blazed a path in offshore refugee policies, while the European Union has started to experiment with a similar project in its migrant deal with Turkey.

The international law governing refugees gives the right to anyone who physically makes it to U.S. territory to request asylum. This, rather than trying to hide from border agents, is increasingly what illegal immigration into the U.S. looks like: Migrants, largely from Central American countries, are making their way to the southern border and presenting themselves to border guards, and then requesting legal proceedings, which unfold within the U.S.

That’s the norm today, but the U.S. processing system has moved outside of America’s borders several times. In reaction to the chaos of the post-war exodus from Vietnam, the U.S. instituted a large-scale program in 1979 to process refugee claims within Vietnam. The “Orderly Departure Program” resulted in more than half a million people being brought into the U.S. Similarly, in the 1990s, the U.S. airlifted more than 6,000 Iraqi Kurds to Guam, a U.S. territory, for processing.

An early version of the Mexico plan is the U.S. Naval Station at Guantanamo Bay, which since the 1990s has been used to house migrants intercepted at sea. Under George H.W. Bush, more than 10,000 Haitians intercepted at sea were processed at Guantanamo, with many ultimately resettling in the U.S. Through the Obama administration, Cubans halted on boats under the now-ended “wet foot, dry foot” policy were taken to Guantanamo, where they were said to reside “voluntarily,” without pressure to return home. Those found to be legitimate refugees were resettled to third countries.

But it is Australia that has set the standard for extraterritorial refugee policies in the last two decades. Since the early 2000s, under successive governments from both sides of the political spectrum, Australia has enacted a series of measures to permanently move would-be refugees off its territory. Its policy includes a deal with neighboring island states Papua New Guinea and Nauru, which are now home to long-term camps for those caught trying to enter Australia illegally. Individuals who are found to have legitimate claims to asylum can resettle in the countries they have wound up in, or some third country, but not in Australia. As then-Prime Minister Kevin Rudd put it in 2013, “Any asylum seeker who arrives in Australia by boat will have no chance of being settled in Australia as a refugee.”