It is fascinating to watch other people quarrelling. The onlooker sits at a safe distance, enjoying the angry exchanges, marvelling as the quarrellers’ noisy irrationalities and inconsistencies grow apace and enjoying a smug sense of superiority: ‘You’d never catch me losing my temper over such a silly issue like them’.

Perhaps the onlooker then starts to worry that things might spiral into a violent confrontation. There is an obvious way out, fair to both sides, if only the silly people could see it. Temptation. Why not step in and offer to calm things down? Since time began there have been disagreements between people, quarrels, disputes and fights, sometimes full-scale wars. And ingenious ways have been found to bring in people not immediately involved in the problem to try to restore calm, or at least bring about a more peaceful way forward.

So Mediation has a long history. Look at the Roman words still used today: internuncius, medium, intercessor, philantropus, interpolator, conciliator and interlocutor, not to forget the word mediator itself. These days, mediation takes many forms. A sprawling body of theory and practice has developed. Very broadly speaking, outside interventions fall into two categories:

• Those in which an outside person proclaims a fair outcome  which the parties to the dispute are expected (or required) to accept. Options range from ‘arbitration’ to a legal ruling from a court.

• Those where the outside person does not offer any view on the dispute, but rather privately encourages the parties to look at different, wiser options and settle the dispute themselves. This is the essence of ‘mediation’.

In the UK, classic commercial mediation technique plays down raw emotion. An independent mediator talks confidentially to the parties in turn, to identify areas of potential compromise. In other countries, the parties are brought together and furiously argue until exhaustion sets in – a draining experience but (it is claimed) one more likely to achieve not only a practical settlement but important emotional ‘closure’ as well.

Whichever school of mediation is used, the same questions keep appearing: What is the role of confidentiality? Can any mediator be truly neutral? Is it better to have a mediator who knows the issues and maybe the parties themselves, or someone completely independent and largely ignorant of the background? Should a mediator merely listen carefully but not get ‘involved’? Or better to be tough, pushing parties towards a deal?

Most importantly, what is success? A full settlement? Or is it enough to narrow differences and steer the whole problem into more peaceful processes? All these questions and plenty more have featured in diplomatic disputes down the ages.

Take the First Macedonian War of 209-205 BC between Philip V of Macedon and the Aetolian League plus its Roman allies. Smaller Greek states such as Ptolemaic Egypt, the Rhodian Republic and Athens stepped in and helped bring about peace. But were they doing so as part of a scheme of their own? A few years later they were egging Rome on to attack Macedon again – resulting in the second Macedonian War.

Some two thousand years later, in 1812, the English and French found time while fighting each other in the Napoleonic wars to bully the annoying new so-called United States of America. The Russian Tsar offered to mediate. The Europeans declined. After a short but excellent war, during which the British burned Washington and briefly chased away President Madison, a peace treaty was agreed in 1814.

Sometimes mediation happens as a conflict ends. Hence in 1905 President Theodore Roosevelt helped negotiate the peace settlement for the Japan/Russia War, after the Battle of Tsushima when Japan defeated a Russian fleet which had sailed all the way from the Baltic Sea, attacking British fishing boats in the North Sea by mistake along the way.

One way to be a credible and efficient mediator is to appear unambiguously peaceful and reasonable, with no practical interest in the outcome. Norway has done well in recent years by projecting this national image to make an impressive contribution. As the New Statesman put it in 2003: ‘Spin the globe and put your finger on a conflict, and there is a chance you will find a Norwegian trying to resolve it…Norway has become a peace superpower.’ Norway can point to significant progress in a number of high-profile conflicts, including the Middle East (most notably the 1993 Oslo Accords) and Sri Lanka.

Likewise people armed only with religious authority can make a positive difference. A classic modern example is the Beagle Channel dispute between Chile and Argentina over islands and sea areas at the very foot of South America. The issue boiled over in December 1978 when Argentine troops seized disputed territory. Pope John Paul II quickly sent a personal envoy to the two capitals, a move which led the two countries to resolve the problem peacefully. After six years hard work (and the intervening Falklands War between the UK and Argentina, when Chile sided with the British) this mediation brought about a bilateral Treaty of Peace and Friendship.

That sort of high-profile religious diplomacy is exactly what the Quakers strive to avoid. Early Quaker leaders, such as Robert Barclay, believed that those who accepted Christ’s message would naturally reject all forms of warfare. In 1678, Barclay wrote An epistle of love and friendly advice to the ‘ambassadors of the several princes of Europe, met at Nimeguen to consult the peace of Christendom’, urging them ‘to give up their evil ways’.

A century later, Barclay’s grandson and other Quakers tried hard, but unsuccessfully, to prevent war between the American colonies and London. Quaker Joseph Sturge had rather better results in 1850, persuading Danish leaders towards recognition with the duchies of Schleswig-Holstein. His later interventions to try to stop the Crimean War of 1853-1856 were welcomed by Tsar Nicholas but roundly condemned in the British press. Undaunted, the Quakers made many attempts to promote peace as the Machine Age wars swept the planet. The British and American Friends won the Nobel peace Prize in 1947 for their work in post-war relief operations.

Private Quaker initiatives continue to this day, having a special approach based on quiet listening aimed at helping people involved achieve inner peace and so be more receptive to new ideas. But this requires a level of self-denial not always found in professional diplomats. Quaker peace worker Mike Yarrow says: ‘It takes a certain amount of courage to intervene in a complicated, dangerous situation…to keep it up the conciliator needs some sense of satisfaction. All this can readily build up to a feeling that the individual is essential to the resolution of the conflict, and even that he or she has the solution. Such feelings are fatal to this kind of unofficial effort.’

The Middle East’s profound problems of identity and existence continue to frustrate international peace efforts, and have done from the start. In 1948, Swedish diplomat and nobleman Folke Bernadotte, famous for rescuing thousands of people from Nazi concentration camps, became the first-ever official UN mediator. Tasked with tackling the Arab/Israel War he was soon murdered by Israeli extremists who thought he supported British and Arab plans to thwart the new state of Israel. His American co-mediator Ralph Bunche won the 1950 Nobel Peace Prize for his work in bringing about the 1949 Armistice in Palestine, the first ‘person of colour’ to win a Nobel award.

Mediators can make a difference (or not) precisely by being seen as close to a process. Hence attempts by a number of Arab or Islamic countries – including Saudi Arabia, Qatar, Egypt and Turkey – to help make progress in the Middle East problem. A US/Norwegian/British group of mediators have tried to bring peace to Sudan, Africa’s largest country. Former British Ambassador to Khartoum, Alan Goulty, saw his familiarity with the country as an advantage for his mediation work: ‘There’s a tendency around the world to blame Britain for their problems. But in the case of Sudan, there is no historical resentment. There’s a flattering approach that “you know us better, so you must help”.’

Part of the problem with official diplomatic mediations is that mediators come from states with their own interests and ambitions. In 2007, a strong team of seasoned diplomats – Germany’s Wolfgang Ischinger for the European Union, plus Russia’s Alexander Bozan-Kharchenko and the USA’s Frank Wisner – led a doomed move to resolve the Kosovo problem. The Serbs and Albanians refuse to budge from their core positions. Worse, the Europeans were divided among themselves over what a fair outcome should be, as were Russia and the United States. These divisions seeped into the mediation process, which failed. Kosovo proclaimed independence. Many countries round the world refused to recognise the new state. Serbia has taken the issue to the International Court of Justice.

Most recently, a heavy effort was made by the Organisation of American States to tackle the Honduras crisis after President Zelaya was bundled out of office last year and ended up seeking asylum in Brazil’s Embassy in Tegucigalpa. However, many Latin American leaders, and indeed Washington, at first sided openly with Zelaya, making the new Honduras leadership distrust their good offers. Eventually, the Obama administration took a more nuanced approach and helped negotiate a political settlement that has led to successful new elections. Most important of all, Brazil has its Embassy back.

One way or the other, diplomats have formidable personal experience and insight in looking at international disputes, trying to find ways to break deadlocks and build bridges.