With an executive order signed on Friday, President Trump began implementing the ‘extreme vetting’ of Muslims he promised during his campaign. All refugees are now barred from entering the US for 120 days. Syrian refugees face an indefinite ban. For 90 days, all entry has been suspended for citizens of seven Muslim majority countries: Syria, Iraq, Iran, Sudan, Libya, Somalia and Yemen. Yesterday, it was confirmed that the ban on entry includes people with green cards who happened to be out of the US when the order was signed. They cannot return home.

In response, protesters gathered at airports across the US: in New York, Chicago, San Francisco, Washington. At JFK, a large crowd chanted ‘Let them in.’ Last night, in response to a legal action from the American Civil Liberties Union, a federal court in Brooklyn granted an emergency stay on the executive order, preventing the deportation of those who had been detained at airports even though they had valid visas. The government lawyers defending the order were asked how many people were at risk of being sent back to countries where they might be in danger. They said they did not know.

My aunt and uncle and their three children live in the US. They all left Iraq after the 2003 invasion. My cousin Ali, who arrived in the US first, in 2005, is married to an American woman, Rachel. They live in New Haven, where he has a postdoctoral fellowship. It took his parents ten years to get green cards. They arrived at the end of 2015, having missed the weddings of two of their sons.

My 96-year-old grandmother lives in Amman. (Before the US invasion, she lived in Baghdad.) Ali’s parents make a regular trip to Jordan to see her and collect their pensions. If they went now, they would not be allowed to return to their homes in the US. Nor do they know when they will be able to. Meanwhile, Ali and his brothers are left in confusion. One of them, Harith, has US citizenship. But the other two have green cards: if they were to leave the country they live in, they would not be allowed to return. Like many others, they are wondering what comes next. Is this ban only the first step?

‘This is after only seven days that he’s been in power,’ Ali said when I spoke to him on the phone. ‘I can't imagine what will happen over the next four years.’ He told me that a friend of Rachel’s, an Iranian student doing a master’s degree in California, was in Vienna visiting family when the ban came into effect. She was turned back on her way back to California. ‘Everyone’s very nervous and upset,’ he said. ‘I’ve been getting calls all day from friends, asking if I’m OK.’

It may be tempting to see Trump’s order as an unprecedented break with previous policy, but the list of countries whose citizens are now banned from entering the US is based on a bill that President Obama signed into law in December 2015. The Visa Waiver Program Improvement and Terrorist Travel Prevention Act restricted access to visa waivers for people who had recently visited Iran, Syria, Sudan or Iraq – or held dual citizenship with one of those countries – making it much more difficult for them to visit the US. Two months later, the Obama administration added Libya, Somali and Yemen to the list.

Like all settler colonies, the US has a long history of fixation on the colour of the skin of those who enter and, especially, reside within its borders. Through a series of measures dating back to the 1882 Chinese Exclusion Act – which wasn't repealed until 1943 – Asian immigrants have been targeted. In 1920, the journalist Lothrop Stoddard wrote a book in which he denounced the First World War as ‘nothing short of a headlong plunge into white race-suicide’, because it had weakened ‘white solidarity’ vis-à-vis the ‘coloured world’. He warned of the ‘rising tide of colour’, predicting a ‘tremendous and steadily augmenting outward thrust of surplus coloured men from overcrowded coloured homelands’.

Stoddard’s book, a bestseller, was praised by President Harding (it was later satirised in The Great Gatsby). A year after its publication, the Emergency Quota Act set fixed quotas for immigrants based on their country of origin, in an attempt to prevent a demographic shift away from northern Europeans. Panics over migration in the US have often erupted suddenly, framed as emergencies.

Yet the speed of recent developments is still disconcerting. When Trump called for a Muslim ban on the campaign trail, he was roundly denounced. Mike Pence, now Trump’s vice president, tweeted in December 2015: ‘Calls to ban Muslims from entering the US are offensive and unconstitutional.’ Paul Ryan, the speaker of the House of the Representatives, agreed with Pence then that it ‘is not what this country stands for.’ He agrees with Pence now, too: ‘Our number one responsibility is to protect the homeland,’ he said on Friday, supporting the executive order.

Pressed on the question of the ban during her trip to Turkey, Theresa May would say only that ‘the US is responsible for the US policy on refugees.’ With growing criticism from her own party, her spokesman later released a statement affirming she disagrees with the policy. Meanwhile, Ali told me he has no idea what will happen next, but he and Rachel are thinking about what they will do if it comes to the worst. ‘She’s said she will come with me,’ he said, ‘if I have to leave.’