Portugal Colonial - Catching the world's most wanted: the ICC's impossible task

Backed by 125 member states, the jurisdiction seeks to prosecute individuals responsible for the world's gravest crimes when countries are unwilling or unable to do so themselves.

The wheels of international justice grind slowly, as evidenced by the court's low conviction rate.

However, it’s not all about the final judgement, experts say.

The mere fact of pursuing alleged perpetrators of atrocities sends a message that the international community is determined to fight impunity.

- Catch me if you can -

Since it began work in 2002, the ICC has opened 32 cases for alleged war crimes, crimes against humanity, genocide and offences against the administration of justice.

Fourteen of them, or roughly 40 percent, are ongoing, in most cases because the suspects are still at large.

Without a police force, the Hague-based court is unlikely to catch them soon.

Of the 60 arrest warrants issued since 2002, only 21 had been carried out before Duterte's arrest.

The ICC relies on states to apprehend suspects.

But the incentive for them to cooperate is low because the court has "nothing to offer in return, except a commitment to seeing justice served", former ICC adviser Pascal Turlan said.

The court's wanted list includes Russian President Vladimir Putin, Israeli Prime Minister Benjamin Netanyahu and Ugandan warlord Joseph Kony. All three are accused of war crimes.

Russia is one of dozens of nations, including the United States, Israel and China, that do not recognise the jurisdiction of the ICC, hampering its ability to investigate their nationals.

But some member states also defy its authority by, for instance, refusing to hand over suspects.

"When states don't like what the ICC does, they don't often cooperate," said Nancy Combs, professor of law at William & Mary Law School in the United States.

- 11 convictions, all Africans -

ICC spokesperson Fadi El Abdallah stressed that the court's role is not to go after all suspected war criminals but to "encourage nations to deal with their own cases".

Each case comes with a unique set of challenges, from interference by national governments to witness intimidation.

The latter caused the case against Kenya's former deputy president William Ruto to fall apart in 2016, according to a former chief prosecutor.

These challenges partly explain the court's low conviction rate.

Since its inception it has handed down 11 guilty verdicts, mostly against officials from the war-torn Democratic Republic of Congo (DRC), and four acquittals.

All those judged were Africans, leading to accusations that the ICC is unfairly targeting the continent.

Combs pointed out that some African countries, including Uganda, Ivory Coast and the DRC, had referred their own wars to the court for investigation in the early days, while other cases had been instigated by the United Nations Security Council.

"The ICC has diversified a lot but non-African states have resisted ICC jurisdiction more fiercely," she pointed out, citing Russia as an example.

A.P.Maia--PC