Professor Mia Swart is Visiting Fellow at Edge Hill University and Visiting Professor at Wits Law School. A former producer at Al Jazeera, she writes on human rights and international crimes.

As the International Criminal Court turned 20 on 1 July, there is more reason than ever to be sceptical about the success and legitimacy of this court.

What a difference 10 years makes. In June 2012, I spoke at a conference celebrating the 10th anniversary of the creation of the International Criminal Court (ICC). The conference was held at the Foreign and Commonwealth Office in London.

In 2012 the mood around the ICC was still celebratory, inviting comparisons with Nuremberg and other "triumphs" of international justice. On the day of the conference Aung San Suu Kyi paid a visit to the same building. Colleagues excitedly reported sightings of one of the world's most illustrious human rights defenders. Although the ICC's fall from grace has not been as dramatic as that of Aung San Suu Kyi, the ICC inspires little of the hope and enthusiasm it did in those heady early days.

It did not take long for the ICC to disappoint. In its very first case, a case against...