Out of curiosity, I researched a little what happened to former secretaries-general of the United Nations after they left New York with a few clicks on Internet sites, including Wikipedia.

Here's what I learned:

Kurt Waldheim of Austria, who served as the UN chief 1972-1981, first unsuccessfully sought the presidency of his country in 1981 immediately after he finished his second term with the world body.

Five years later, he was elected president in a direct vote to become the head of state with authority to appoint the prime minister under the 1945 Austrian constitution.

Javier Peres de Cuellar of Peru (1982-1991) ran for president in 1995, but was defeated by Alberto Fujimori.

He later served as prime minister from November 2000 to July 2001.

His successor at the UN, Boutros Boutros-Ghali of Egypt, was considered as a possible contestant for the nation's highest office following the ouster of Hosni Mubarak during the turmoil of "Arab Spring," but the Coptic Christian was soon sidelined by the surge of Islamist force.

Kofi Annan has remained a giant figure in Ghanaian politics since his retirement from the UN after two consecutive terms (1997-2006).

He was seen as a potential candidate for president, yet, he kept himself in the arena of international affairs, serving as, among others, the UN and Arab League envoy to Syria.

The first UN Secretary-General, Trygve Lie of Norway, took some ministerial posts in Oslo even after he resigned from the UN job in November 1952.

He was antagonised by Moscow for his role in the creation of the UN Command during the Korean War.

His successor Dag Hammarskjold of Sweden died in a plane crash in 1961.

The third to take the post, U Thant of Burma (now Myanmar), spent his last years quietly abroad as Ne Win's military government was ruling his country.

Ban Ki-moon, the eighth UN secretary-general and from South Korea, is to finish his second term at the end of this year and must also be keenly studying the paths of his predecessors as he envisions his future these days.

Their countries of origin are quite diverse in terms of geographical distribution, historical pathways and present roles in the global community, little in common with the Republic of Korea's.

Yet, each individual case could encourage or discourage our man in the UN if he was searching for guidance for the next chapter in his life.

The footsteps of those former UN chiefs were varied but in no way seem to be deterring Ban from setting his sight on Seoul's Blue House.

The UN Charter prohibits the staff of the world body from being involved in the domestic politics of any country and a 1946 UN resolution specifically says that the secretary-general should not be offered, or accept, a government job "immediately on retirement."

He could believe that a year's time from his UN exit to the December 2017 election may not be judged "immediate."

On his latest visit to his home country from May 25-30 (with two days of absence for a trip to Japan), Ban provided ample fodder for journalistic speculation with his rather bold remarks and wide strides to politically significant locations.

His first formal meeting was with members of the Kwanhun Club, a fraternity of senior journalists that used to offer opportunities for presidential hopefuls to make public their bid for the highest office.

In a roundtable, he told the media editors that he would be "contemplating what to do as a Korean citizen" upon finishing his tenure as the UN secretary-general next year.

He then mentioned his "competence that may be available for relations with North Korea" and "Korean politics in want of a leadership of integration."

He compared his age of 72 to that of US presidential candidates "who also are in their 70s."

Most conspicuously, Ban, a native of the central Chungcheong Province, was present at some events in Andong and Gyeongju in the southeastern Gyeongsang Province, a politically volatile region which, as the traditional turf of the conservative Saenuri Party, needs to ally with the Chungcheong populace if it seeks to extend its grip on power through the presidential election.

If this was still not enough, he had "clandestine talks" with Kim Jong Pil, 90, who is regarded as the spiritual leader of the Chungcheong people.

With Ban Ki Moon back in his New York office, people here have begun placing bets on him, mostly about his chance of winning in the election, rather than about the possibility of his running or about the party that will eventually recruit him - the subjects of debate over coffee until early this year.

If things have become clearer in spite of his still cautious choice of words, a process has just begun, for a full inventory of his assets and accounting of liabilities by the media and the adversaries that he helped define through his visit in May.

UN secretary-general is a most honourable job that Ban Ki Moon has performed no doubt with superlative diligence and dedication, earning a fair degree of trust from world leaders with the modest, unsophisticated manner which may lack a charismatic quality, but can sufficiently prove his personal integrity.

Still, the United Nations is essentially a diplomatic stage where business is done according to treaties, conventions, protocols and established principles while what applies to domestic politics is just the law of the jungle.

Predators are poised to eat a ram from the pasture.

Since last year, Ban Ki Moon has continued to enjoy approval rates as the next president in the range of some 30 per cent, nearly twice higher than that of the next popular competitor.

Those figures will henceforth be adjusted to more realistic levels when the Korean public regards him as a part of the political machine instead of something of a white knight to clean up the mess in Korea's strife-torn political arena.

No one at this moment can say with certitude what the lot ahead of Ban Ki Moon will be.

If I were to give advice to him, it is that the UN secretary-general must keep himself from the temptation to do something that will have any degree of echo in his home country, such as renewing efforts to make a visit to North Korea. His motivation will be doubted whatever the outcome.