Consider this alternative history: Shortly after the 1980 change in presidential administrations, President Reagan issues an order to suspend resettlement of Cambodian refugees who fled mass murder at the hands of the Khmer Rouge. The reason for doing so, he says, is because they can't be properly vetted.

After a few months, the suspension is not lifted because the government of the People's Republic of Kampuchea fails to meet a new U.S. requirement to provide information that the U.S. says it needs to vet refugee claims. The Thai government, with the blessing of the U.S. government, then dumps hundreds of thousands of Cambodians into what they claim is a "safe area" along the border where the Khmer Rouge still holds sway.

One can only imagine the fate of many of our Cambodian friends and neighbors if the United States had chosen that path three decades ago.

President Trump's Jan. 27 executive order is not imaginary. The reality of it hit refugees worldwide immediately. It suspends the U.S. refugee program entirely for 120 days, and indefinitely for Syrian refugees. Even if resumed, it will also cut refugee admissions to the U.S. by more than half this year and establish a preference for persecuted religious minorities.

But beyond that, the part of the order that bans entry of any nationals of Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen for 90 days also looks as though it could have a devastating impact on refugees — and not only from those seven countries. The order states that after 90 days, any foreign nationals will be barred from entry if their home country does not provide "the information needed ... to adjudicate any visa, admission, or other benefit" under U.S. immigration law. That would presumably include refugee status.

A refugee is defined in U.S. and international law as a person with a well-founded fear of being persecuted who does not have the protection of their own government. Often, it is their governments, such as that of Bashar Assad in Syria, that are their persecutors. To expect that a government would provide information about the people it is persecuting and other relevant information to enable the United States to adjudicate the persecution claim is ludicrous.

The U.S. refugee program brought hundreds of thousands of Soviet Jews to the United States without asking the Soviet Union to provide information about them. Realizing that it would be pointless to ask the government of the indicted war criminal Omar al-Bashir to provide information about the Lost Boys of Sudan or refugees from Darfur, U.S. officials found other effective ways to screen them for admission. The list goes on.

For years, U.S. officials have processed refugees for resettlement with intense — yes, extreme — vetting to ensure that no refugee admitted to the United States would do this country harm. And they have often done this — of necessity — without the cooperation of the home governments that persecuted them. The Departments of State, Defense and Homeland Security conduct multiple and overlapping screening of all refugee applicants together with other US intelligence, security and law enforcement agencies, including the National Counterterrorism Center and the Federal Bureau of Investigation, as well as Interpol and with the cooperation of the governments hosting refugees in the countries of first arrival.

In fact, the existing vetting has been successful. Not one of the more than 3.2 million refugees admitted to the United States in the 40-year period from 1975 to 2015 has committed a single fatal terror attack on an American, according to a recent Cato Institute study.

Trump's executive order is an insult to thousands of U.S. government officials who have worked conscientiously both to protect refugees and the U.S. homeland. It is also an affront to the values of compassion, generosity and leadership that the State Department says the resettlement program is intended to promote.

But most astounding is its illogic of requiring a persecutor to vouch for the person he is persecuting. Looking ahead 120 days from now, this could be the greatest threat that what is now a temporary halt will become a permanent bar to those most needing rescue.