The U.S. Supreme Court last week issued a green light for discrimination against American soldiers, sailors and Marines who are transgender — a decision that means the Trump administration can begin enforcing a heartless policy that will expel legions of patriots who have served their country well. Many new recruits will also be turned away.

The policy will upend the lives of potentially thousands of men and women in uniform and bring careers to a cruel and premature close. For many other troops, the policy means either having to relinquish their uniforms or once more having to hide their true gender identities.

Congress should demand that the Trump administration reverse course on this pointless ban and restore the 2016 directive that permitted transgender troops to serve openly, seek ordinary medical care and do so as men or women regardless of the gender they were assigned at birth. The move had signaled progress and long-overdue acceptance into the mainstream not just for troops, but for the transgender community as a whole. Its devastating reversal will be just as broadly felt.

The Trump administration’s ban of transgender people in the military has been challenged in at least four federal courts and was put on hold while courts considered whether it was legal. Last week’s decision by the high court, on a 5-4 vote without any commentary, quashes a series of stays ordered by lower district and appellate courts, allowing the policy to take effect while litigation continues.

This course will only lead to instability. Since there’s a very real chance the policy will eventually be overturned, the administration should delay implementing it until its legal status is confirmed, as ordered last July by a panel of the 9th U.S. Circuit Court of Appeals.

Trump’s initial announcement, via tweet, that he planned to expel transgender troops and new recruits from the armed services took almost everyone by surprise — including then-Defense Secretary Jim Mattis. It was a blatant effort to pay political favors to the religious right and others in America who have increasingly targeted transgender individuals in recent years.

No short-term political gains from such a sop are worth such callous treatment of our troops.