Ditchley Park is a sublimely beautiful 18th century mansion in Oxfordshire where the Ditchley Foundation holds impeccably well-run conferences on international affairs. Last weekend, the state of international law was debated by some of the world’s leading experts. I was there too.

Under the house rules, I may report, in general terms, what was said – but not who said it. I can tell you, for example, that most of those present seemed pretty satisfied with the way that international law was working. If we are talking about the resolution of cross-border trading disputes or the enforcement of international treaties, I would not disagree.

But there was a distinct reluctance to confront some of the most high-profile failures of international law, in particular the International Criminal Court (ICC). Though disappointing, this complacency comes as no surprise. Since the court opened for business nearly eight years ago, the 111 countries that run the ICC – the states parties to the Rome statute – have shown little willingness to tackle its problems, with the result that it has not yet completed a single trial. I suspect that these states will be equally uncritical when they assemble in Uganda next week to review the court’s work and discuss how its jurisdiction could be expanded to cover ‘the crime of aggression’.

Take the appointment of judges, for example. Some of those nominated by states had no prior courtroom experience whatsoever. The Japanese judge Kuniko Ozaki spent most of her career working for her country’s foreign ministry. But at least she was an academic lawyer. Her predecessor, Fumiko Saiga – who died after little more than a year in office – was not even legally trained. And yet the Japanese had claimed that Saiga would qualify for the ‘highest judicial offices’ in her own country. I am sceptical of the Japanese government’s response that its diplomats are the only potential candidates with sufficient English.

Given this lack of experience, war crimes tribunals naturally try to ensure that the trials themselves are conducted by judges who do not have to learn on the job. Academics and diplomats are normally banished to the appeals chambers, where it is thought they can do the least harm. Far from it: their inexperience of courtroom procedures risks producing inappropriate or impractical rulings.

For example, it was an appeals chamber at the Yugoslav war crimes tribunal which decided early in 2002 that Slobodan Milosevic should answer all three sets of charges against him in a single trial, overturning a plan by the trial judges to reach a verdict on the Kosovo case before moving on to Croatia and Bosnia. As a result, Milosevic was still on trial when he died four years later. The Yugoslav war crimes tribunal will always be remembered for its failure to convict the country’s president.

Back at the ICC, three of the 18 judges are now regarded as ‘contaminated’ – meaning that they must be excluded from certain cases. One worked in the ICC prosecutor’s office from 2003 to 2006 and so cannot try defendants that she investigated. And two long-serving judges were ‘promoted’ to the appeals chamber, contrary to the Rome statute. They cannot decide appeals in cases they had previously heard.

This contamination can only add to the delays that Sir Adrian Fulford, the British judge at the ICC, describes as ‘corrosive’. Fulford, who was not at Ditchley, is presiding over the trial of Thomas Lubanga, an alleged Congolese warlord accused of conscripting child soldiers. That trial is likely to take two years – a year longer than the judge had intended or expected.

In a little-reported speech this month, Fulford rejoiced at the existence of international courts. ‘But I bemoan the snail’s pace at which they sometimes seem to proceed,’ he said, adding that ICC procedures were ‘sometimes reminiscent of the drawn-out intricacies of a minuet at the court of Louis XIV’.

However, Fulford thought it dangerous for a judge in his position to use his court as a laboratory and try out new procedures. Appeal judges might declare a mistrial. Only the states parties could change the rules.

The biggest problem for the ICC is its prosecutor, Luis Moreno-Ocampo. ‘He’s a Latin,’ someone told me with a knowing look – as if that explained everything. There was a widely held view that Moreno-Ocampo has politicised the court, thus reducing the chances that countries such as the US will ever join it.

The prosecutor’s worst mistake was to announce in 2008 that he would be seeking to have the Sudanese leader, Omar al-Bashir, arrested for genocide, war crimes and crimes against humanity. This empty gesture has left western diplomats with something of a dilemma: should they attend the newly re-elected president’s inauguration in Khartoum today, given that he is a fugitive from international justice?

In what was seen as an attempt to appease the Muslim world, Moreno-Ocampo then let it be known that he was considering whether he had jurisdiction over Israeli military operations in Gaza. The prosecutor has now spun this out into a full-scale investigation. As I explained here a year ago, there would be jurisdiction only if Palestine were a ‘state’ in international law – a claim that not even a Palestinian lawyer would make.

Even so, others at Ditchley insisted that the ICC was a fledgling institution, representing only a tiny sliver of international justice. The real test was ‘complementarity’ – the extent to which states would now prosecute war criminals themselves. And on this, as with international law generally, there were grounds for optimism.