The Former Nigerian President, Olusegun Obasanjo is officially in Senegal as the head of a joint African Union and West African regional bloc election observation mission, but his experience in brokering disputes elsewhere in Africa is likely to play a prominent role.He told reporters at the airport upon his arrival that although his primary reason for being in the country is to monitor the election, he will not hesitate to step up and take a proactive role in order "to prevent what is preventable.""This country is a very beautiful country and nothing should be done to destroy it," he added.As a former United Nations envoy, Obasanjo played various roles in mediating conflicts elsewhere on the continent, and last year traveled to Ivory Coast to tell ex-Ivorian President Laurent Gbagbo to relinquish power after losing that country's election.Senegalese newspapers have been quick to remind readers that Wade himself counseled Obasanjo not to run for a third term. Obasanjo is remembered for overseeing the first peaceful transfer of power from a military to a civilian government in Nigeria's history, as well as for stepping down in 2007 after two terms.Asked at the airport to comment on that incident and what message he is bringing Wade now, Obasanjo replied: "If President Wade advised me not to run for a third term - which I was not running (for) - maybe he can best advise himself," he said.In the hour before his arrival, police fired tear gas to disperse demonstrators as they took to the streets and set fire to tires in a show of anger over the candidacy of the country's 85-year-old leader.Despite President Abdoulaye Wade's age and the growing unrest, he has continued to say he will run for a third term in Sunday's election even though the constitution was revised to impose a two-term maximum.Six people have been killed in clashes that have erupted regularly over the past three weeks since the country's highest court ruled that the elderly leader could stand for a third term.The street violence that has disrupted daily life in Senegal is highly uncharacteristic for this normally placid nation, long held up as a model of tolerance and stability. Many worry that if Wade is declared the winner of Sunday's ballot, the unrest will spread.Jefferson Sackey, Snr. International Correspondent Dakar, Senegal