A detainee sits with a soccer ball at Otay Mesa immigration detention center in San Diego, California. Lucy Nicholson/Reuters

Trump's "zero-tolerance" immigration policy violates the international human rights law that protects immigrants, refugees, and especially children.

Even after his executive order, he maintained requirements to prosecute or detain immigrants who may have entered the country unlawfully — including children and asylum-seekers.

The United States agreed to the Convention Relating to the Status of Refugees when it joined 145 other nations in ratifying the Protocol Relating to the Status of Refugees in 1968.

The US Constitution makes the rules in these treaties binding US law, prohibiting countries from punishing refugees for entering illegally if their life or freedom was threatened at home.

After public outcry and political pressure, President Donald Trump ended the practice of separating children from their families at the border in an executive order signed on June 20.

However, he left in place requirements to prosecute or at least detain immigrants who may have entered the country unlawfully — including children and asylum-seekers. On June 25, border control officials announced that families crossing the border would not be detained until sufficient detention space was made available. Individuals traveling alone will continue to be prosecuted.

Meanwhile, the White House insisted there had been no retreat from its "zero tolerance" policies. The military has agreed to provide additional space to detain 20,000 immigrants for extended periods. These policies are unlawful.

Through my research on human rights, I am very familiar with the pattern of governments exploiting fear to justify rights violations. They nearly always portray their victims as evil, as threats, or as criminals, not worthy of basic human dignity. For example, the George W. Bush administration relied on the fear of terrorism to justify the kidnapping, torture, and cruel and inhuman treatment of detainees. Courts around the world have since condemned these violations of human rights law.

The US is now doing something similar with its immigration policies. This month President Trump defended his "zero tolerance" immigration policies by claiming his opponents "don't care about crime and want illegal immigrants, no matter how bad they may be, to pour into and infest our country, like MS-13." MS-13 refers to Mara Salvatrucha, an international criminal gang that, ironically, started in Los Angeles and spread across the continent.

These characterizations provide the pretext for allowing the country to defy fundamental principles of international law in the way it treats immigrants.

Detaining and prosecuting asylum-seekers

Detainees at Otay Mesa immigration detention center in San Diego. Lucy Nicholson/Reuters

The United States agreed to the Convention Relating to the Status of Refugees when it joined 145 other nations in ratifying the Protocol Relating to the Status of Refugees in 1968. These treaties define a "refugee" as a person fleeing her or his country of origin because of a well-founded fear of persecution on the basis of race, religion, nationality, membership in a particular social group or political opinion.

Under the treaties, refugees have the human right to request asylum. In addition, these treaties forbid countries from expelling refugees or from sending any immigrants to countries where their life or freedom would be threatened on the basis of the same five categories.

These treaties also prohibit countries from punishing refugees for entering illegally if their life or freedom was threatened at home. Despite the fact that our Constitution makes the rules in these treaties binding US law, the Trump administration is treating asylum-seekers like criminals. When the US government prosecutes or imprisons these asylum-seekers, it violates the rights protected in the two treaties that recognize the human right to seek asylum.

Indefinitely detaining immigrant children

All immigrants, including refugees, are protected by international law, especially children.

Another treaty that protects those caught up in the Trump administration's immigration policies is the International Covenant on Civil and Political Rights. It was ratified by the United States in 1992. It mandates that when a government arrests, detains or imprisons a person it must treat them humanely and with respect for "the inherent dignity of the human person."

When the US detains immigrants indefinitely, especially if they are children, it violates the covenant. This is clear from findings issued by the American Academy of Pediatrics: "Conditions in US detention facilities, which include forcing children to sleep on cement floors, open toilets, constant light exposure, insufficient food and water, no bathing facilities, and extremely cold temperatures, are traumatizing for children."

According to the academy, the effects of detention on children and parents often include "anxiety, depression and post-traumatic stress disorder."

A detained immigrant child watches a cartoon while awaiting the arrival of US first lady Melania Trump with other young detained immigrants at an immigration detainee processing facility in Tucson, Arizona, Leah Millis/Reuters

For the 2,300 children who were separated from their parents at the border, the effects are even more harmful. In a recent article in the New England Journal of Medicine, pediatrician Dr. Fiona Danaher writes that separation can hinder the development of children and cause lifelong physical and mental illness.

Detaining families, parents or children indefinitely disrupts the very fabric of the family. The covenant explicitly recognizes the fundamental right to family life. It prohibits governments from interfering with the family and requires them to protect children and their connections to their family regardless of their national origin.

The US currently has more than 10,000 children detained, who currently spend an average of 56 days in detention centers, according to The Washington Post. According to 2017 data compiled by the Global Detention Project, the United States has more than 300,000 immigrants detained overall, more than 40,000 of whom are asylum-seekers.

With President Trump's new order calling for indefinite detention, these numbers are sure to climb, especially when more detention space is made available. The covenant expressly forbids detaining immigrants this way. It guarantees "the right to liberty" and prohibits "arbitrary arrest or detention." It requires states to allow anyone detained to challenge his or her detention "before a court … without delay."

Tenets of US law

The treatment of immigrants raises a number of conflicts with domestic law as well.

Detaining children indefinitely violates a 1997 court settlement that requires the release of immigrant children within 20 days.

On June 24, President Trump called for the immediate deportation of all unlawful immigrants without any court review. In addition to violating the laws discussed above, this would violate the due process clause in our Constitution which provides that the government may not deprive anyone of their "life, liberty, or property, without due process of law."

In February, the Supreme Court refused to decide the legality of detaining certain asylum-seekers and other immigrants for extended periods without bail hearings. Justice Stephen Breyer dissented and argued that detaining immigrants for extended periods without any judicial review was unconstitutional. He explained, "The Due Process Clause — itself reflecting the language of the Magna Carta — prevents arbitrary detention," and "freedom from bodily restraint has always been at the core of the liberty protected" by law.

Unlawful prosecution and detention policies are alive and well. Make no mistake, away from the border, the US will continue to strip children from their parents by locking them up and deporting them.

There is no international police force to punish the United States for violating its treaty obligations. If recent cases are any indication, the Supreme Court will likely let the government get away with even the most egregious constitutional violations.

These legal principles exist for a reason. History teaches all too clearly that they exist because without them tyranny flourishes and the least powerful among us suffer.