ABOUT A MONTH ago, the diverse coalition of people who campaign for the welfare of ancient religious communities in the Middle East experienced a moment of success when Donald Trump signed legislation aiming to help groups in Iraq and Syria that had been targeted for genocide by Islamic State (IS). The president declared that he was signing the bill because “IS has committed horrifying atrocities against religious and ethnic minorities in Syria and Iraq, including Christians, Yazidis, Shia and other groups.”

This was a high point in a protracted lobbying effort by a coalition that included the energetic, upwardly-mobile diaspora of Middle Eastern Christians; conservative American Christians who feel their co-religionists are under threat from fundamentalist Islam in many parts of the world; and people who advocate the general principle of religious freedom, regardless of which groups are being persecuted and who the persecutors are. The Iraq and Syria Genocide Emergency Relief and Accountability Act, which Mr Trump signed, was introduced by Chris Smith, a Republican congressman. He has worked to enforce and broaden the legislation that binds American governments to monitor and promote liberty of belief in all countries.

But the euphoria did not last long. Among supporters of the region’s religious minorities, Mr Trump’s announcement on December 19th that American troops would be withdrawn from Syria drew immediate cries of alarm. Father Emmanuel Youkhana, a priest of the Assyrian Church of the East, said that for Christians in the area an abrupt American pullout could “open up the gates of hell” and reverse any benefit from the new American law. The Free Yazidi Foundation, based in the Netherlands, also voiced fears that minorities could again find themselves highly vulnerable. “In the event of a future Daesh storm gathering pace in Syria, Yazidi forces cannot be left again as sitting targets, to be attacked, slaughtered and raped,” it said.

Among the minorities and their friends, there are several specific fears. They worry that Turkey, with or without the agreement of other local parties, may overrun the area of north-eastern Syria that has been under Kurdish control, and pave the way for Sunni Jihadists to sweep into the territory. Life has not always been easy for long-established Christian denominations, along with a handful of Kurdish converts to Christianity, under Kurdish administration. Some Kurds were said to be chasing Syria’s Christians away and seizing their lands. But what has survived could be destroyed if hard-line Sunni factions march forward. “Leaving the fate of Syrian religious minorities to the tender mercies of Turkey would risk religious cleansing and likely negate the measures...of the new [American] law to help them,” says Nina Shea of the Hudson Institute, one of America’s leading religious-freedom watchers.

There are other scenarios. The Assad regime has close ties with Christian communities, and minority groups would probably cheer its return. But in the event of confrontation between Turkish-backed groups and Syrian and Iranian forces supporting Mr Assad, small religious minorities could be caught in the middle, says Johannes de Jong, of Sallux, a Dutch-based lobby group. In such a general flare-up, any success achieved in stabilising nearby northern Iraq, and making it safer for minorities, could rapidly be reversed, says Mr de Jong.

A degree of progress has indeed been recorded in northern Iraq, where some Christian communities have recently reoccupied towns in the Nineveh Plain from which they were expelled by IS in 2014. Christmas is again being celebrated after a hiatus under IS rule. A new Catholic archbishop has been named for the city of Mosul, the erstwhile IS stronghold. He is due to be consecrated on January 18th and to take up residence a week later. The hierarch-elect is Father Najib Mikhael Moussa, a French-educated cleric who had already won fame for rescuing religious archives, precious to many faiths, before they were trashed by IS. Promised reconstruction aid from the United States and others including Hungary was slow to materialise, but seems finally to be flowing, boosting the efforts to revive Christianity in the Nineveh Plain. But in Syria, at least, America’s latest steps might be doing more harm to the Middle East’s minorities than good.