It is to the Nobel Committee's credit that on hearing its choice of recipient for this year's Nobel Peace Prize, the response of many people is likely to be: “Martti who?”

Because one of the keys to Martti Ahtisaari's success as a peacebroker over three decades, and across three continents, has been his low profile.

As one of the United Nations's top troubleshooters, Mr Ahtisaari's hallmark has been a dogged, but quiet, diplomacy. The former Finnish President knocks heads together without cracking them, cooking up a workable peace from often unpromising ingredients. In war zones dark with despair, he has shown how a personal commitment to reconciliation can make a pivotal difference in resolving conflicts.

As the UN's special envoy, Mr Ahtisaari nursed Namibia towards a peaceful independence from South African rule in 1990, the capstone of more than a decade of negotiations. Representing the EU he persuaded Slobodan Milosevic, then the Yugoslav President, to accept Nato's terms for ending the Kosovo air campaign in 1999. He then played a vital role in the 2005 peace accord between rebels in Aceh province, Indonesia, bringing to an end three decades of conflict in which 15,000 died. In May 2000 he was chosen to serve as an independent arms inspector in Northern Ireland.

Such successes make Mr Ahtisaari a worthy winner. Nevertheless, after the award of the prize in recent years to the United Nations and Kofi Annan, then its Secretary-General, and later to the UN's International Atomic Energy Agency, the Nobel Committee should beware turning its Peace Prize into a cosy UN preserve.