It is notoriously difficult to gauge how many people have had same-sex experiences but studies have shown that the number admitting to homosexual behaviour is several times greater than the percentage of the population who identify themselves as gay, lesbian or bisexual. In many parts of the world, men will routinely have sex with other men without considering themselves gay. Africa is no different and, with a population of 175 million, one can conservatively estimate that at least 10 million Nigerian men are having sex with men. So aside from the blow to human rights, it is dismal news for the fight against HIV/Aids that Nigeria has just become the 38th country in Africa to boast laws persecuting gay people.

Nigerian authorities began arresting gay men in January, the Daily Telegraph reported, days after legislation was signed by President Goodluck Jonathan criminalising homosexuality and imposing prison terms up to 14 years for breaking the new law. It prohibits homosexuals from even meeting in groups of two or more, bans marriage or civil unions between people of the same sex, and criminalises gay clubs and events.

HIV services that are catering for men who have sex with men will have to stop, a Nigerian activist, Bisi Alimi, told theBBC. As normal sexual behaviour is stigmatised and marginalised, and prevention becomes more difficult, we can expect rates of HIV to soar—and the ranks of Nigeria’s 2.2 million Aids orphans to grow too.

The UN human rights chief Navi Pillay described the law as ‘draconian’. She said: ‘Rarely have I seen a piece of legislation that in so few paragraphs directly violates so many basic, universal human rights.’ The US secretary of state, John Kerry, said the law was ‘inconsistent with Nigeria’s international legal obligations and undermines the democratic reforms and human rights protections enshrined in its 1999 constitution’.

In Uganda, meanwhile, MPs passed an anti-gay bill in December that calls for life imprisonment for certain homosexual acts (human rights campaigners called it the worst such legislation in the world). And in Cameroon a gay man sentenced to three years’ prison for sending a text expressing his love for another man died.

As the west moves towards greater equality between hetero- and homosexuals, and dismantles age-old legal and cultural discrimination, so much of the Commonwealth moves in the opposite direction. Indeed, it has almost become a new anti-imperialist trope.

This erosion of rights would appear to be an area ripe for a robust demonstration of the values enshrined in theCommonwealth Charter. Speaking at a conference on the Commonwealth last year that was co-sponsored by this journal, Amitav Banerji, political affairs director at the Commonwealth Secretariat, said: ‘In the area of human rights, the Commonwealth has made steady progress, including on issues where the membership is seriously divided, such as issues of sexual orientation (LGBTI) … the association believes firmly in non-discrimination on any grounds.’

However, he then qualified this by quoting the Commonwealth secretary-general, Kamalesh Sharma, who told the Human Rights Council in Geneva in 2012 that while the organisation opposed ‘discrimination and stigmatisation … It is for member states to address incompatibilities between Commonwealth values and mostly inherited national laws in these areas.’

The retrograde laws being brought in across Africa (and India too) are not ‘inherited’ colonial laws but the message from the Commonwealth Secretariat seems clear: we might not like these bigoted laws but we’re not going to condemn them either.

Not all human beings have the same human rights, it seems.