Among all the promises of change that swept Barack Obama to power, none seemed more simple, symbolic or easier to implement than his pledge to permit openly gay men and women to serve in America’s Armed Forces.

That promise has been repeated often over the nine months since his election — “don’t doubt the direction we are heading, or the destination we will reach”, he declared last weekend — yet America’s homosexual and lesbian soldiers remain firmly barricaded inside the closet.

The present policy, requiring gays to conceal their sexual orientation or face being discharged, could be overturned by executive order or legislation, yet Mr Obama apparently has little appetite for doing so. No timetable for a change in the 16-year-old policy has been set, and the White House is said to want to delay action into the distant future. Don’t Ask, Don’t Tell has become, under the Obama presidency, Don’t Rock the Boat, Don’t Act.

The law as it stands is a monument to hypocrisy, requiring homosexual soldiers to live a lie and allowing the military brass to ignore reality. With America fighting two wars and recruitment dwindling, it is also astonishingly short-sighted. More than 12,000 members of the US Armed Forces have been discharged since Don’t Ask, Don’t Tell came into force.

The law passed by Congress in 1993 states: “The presence in the Armed Forces of persons who demonstrate a propensity or intent to engage in homosexual acts would create an unacceptable risk to the high standards of morale, good order and discipline, and unit cohesion that are the essence of military capability.”

As Britain’s experience shows, this is demonstrably untrue. A decade ago, when Britain was forced to accept gay troops by the European Court of Human Rights, some predicted heterosexual mutiny. “If the doors were opened to homosexuals, there would be a polarisation, people would be ostracised,” Air Chief Marshal Sir Michael Armitage (retired), the former head of military intelligence, insisted. “Men don’t like taking showers with men who like taking showers with men.”

As it turned out, the vast majority of serving soldiers accepted openly gay comrades without protest or, even more healthily, with benign lack of concern. At least two dozen armies across the world have admitted homosexuals and lesbians without any impact on operational effectiveness or recruitment levels.

Before 2000, some 200 servicemen and women were dismissed each year from the British Armed Forces for homosexuality. All the Services now actively encourage recruitment from the homosexual community by taking part in gay pride events.

Last summer James Wharton, a trooper in the Household Cavalry Regiment, became the first openly homosexual soldier to appear on the front cover of the Armed Forces’ magazine, Soldier. So far from a sustained campaign of bullying, according to Lieutenant-Colonel Colin Bulleid, of the British Army equality and diversity policy branch, homophobia in the Army is now restricted to “the odd prat who behaves inappropriately”.

This transformation of attitudes could hardly be more dramatic, or the contrast with what came before more acute. Historically, homosexuality was punishable by flogging or even hanging, its existence denied or ruthlessly repressed, a lethal source of shame. In the Victorian version of Don’t Ask, Don’t Tell, soldiers were allowed to pursue “unnatural vices” only on the farthest fringes of empire, where no one would notice. In 1903 General Sir Hector Macdonald, the hero of Omdurman and Britain’s most celebrated military figure, shot himself in a Paris hotel room (probably on the advice of the King) after public accusations of homosexuality. His name was expunged from regimental records.

Tom Carver’s new book, Where the Hell Have You Been?, describes how his father, Field Marshal Montgomery’s stepson, escaped from an Italian prison camp in 1943. One of the most touching episodes describes the relationship between two PoWs, Dan Billany and David Dowie, who also escaped, entrusted a handwritten manuscript to an Italian farmer and were never seen again. The document was sent to Billany’s parents after the war. It was, writes Carver, “the only known account of a gay love affair in a Second World War British PoW camp”.

Statistically, there must have been hundreds of similar relationships. Of the five million British men who served in the war, it is likely that some 250,000 were gay or bisexual. Monty himself may have been a repressed homosexual. So far from undermining unit cohesion, gay soldiers not only served valiantly, but often felt obliged to demonstrate additional bravery to counter expectations of weakness.

Yet fear of homosexuality ran cruelly deep. In 1945 the Allied armies liberated the concentration camps and freed Jewish survivors, gypsies and communists. But not homosexuals. An unknown number of men imprisoned by the Nazis for sexual “deviancy” were made to serve out their sentences by the Allied military government. Homosexuals were regarded not as Hitler’s victims but as criminals.

Despite the British Army’s ancient preoccupation with homosexuality in the ranks, Britain’s military history, and her present, clearly prove that homosexuals are quite as good at marching, fighting and dying as their straight comrades.

It takes one sort of bravery to be a soldier, another to be gay in a society such as America, where homophobia is still deeply ingrained; and it takes a rare sort of courage to be both. But in the US, bizarrely, the opportunity to die for one’s country is still restricted by sexual preference. Ending the hypocritical Don’t Ask, Don’t Tell policy requires only political bravery.

Mr Obama came to power promising to tie a pink ribbon around the old oak tree; he is in danger of ending up with a white feather.

Times Recommends

• Bank charges hit us for being human
• Sorry, Father, thou still shalt not steal
• The shed where Santa’s failures go to die