A three-day absence last week for a comprehensive medical check-up in the United Kingdom underlines that health issues are the main obstacle to extending Nigerian President Muhammadu Buhari's rule, in light of his extensive absences in 2017. He is unlikely to leave office in the next year in any other scenario.

• Nigerian President Buhari's declaration that he will stand for re-election underlines the readiness of his APC coalition to avoid a destabilizing leadership contest despite lingering health concerns.
• There is no indication yet of a credible challenge to Buhari emerging either from within the APC or the main opposition PDP.
• A second term in office for Buhari would renew a focus on major rail lines to reduce freight costs, particularly for agricultural producers and exporters.

Nigeria's president, Muhammadu Buhari, arrived back in capital Abuja late on 11 May, after a three-day medical check-up in London aimed at clearing a crucial hurdle to his hopes of standing for a second term in the election due in February 2019. While the nature of the illness that kept Buhari in London for over five months in two separate visits in 2017 remains unknown, he has undergone a remarkable political resurrection. Less than a year after his mooted inability to complete his first term was being openly discussed in Nigeria, after he headed to London for a second prolonged absence, Buhari currently appears to have no strong challenger from either within his All Progressives Congress (APC) coalition or the former ruling People's Democratic Party (PDP).

Buhari told the APC's national executive committee in early April of his intention to stand for office again, shortly before he flew to London for a meeting of Commonwealth heads of state. This was only confirmation of a move that seemed increasingly certain. Buhari had been traversing the country since the start of the year as a clear prelude to announcing his second-term bid, taking in Kano, several states in the north and Middle Belt, and even a first official visit to Lagos in late March. Buhari was endorsed by all 24 members of the APC Governors' Forum on 24 April. The APC was due to hold a conference on 14 May but that has now been postponed until June, allowing more time to resolve any internal opposition to Buhari's candidacy, and further limiting the time available for any challenger to credibly build enough national support.

The only openly declared PDP candidate in the election is serial presidential aspirant Atiku Abubakar, who defected from the APC on 24 November 2017, likely calculating even then that Buhari would seek and win the coalition nomination unopposed. However, Abubakar is almost certain to face strong opposition for the PDP nomination, risking a contentious primary. This would reopen the divisions in a party that has struggled to create an identity in opposition and only elected a new national executive in January after being split for over two years into two factions, both claiming to be the rightful leadership. The most likely challenger to Abubakar now seems the Gombe governor, Ibrahim Dankwambo, who is serving his second term and was the only PDP candidate to win a governorship election in a northern state in 2015.

Outlook and implications
The main obstacle to Buhari winning a second term in office is likely recurring health issues. Although Buhari seems to have made a fairly miraculous recovery from last year - emphasized by his busy schedule of domestic and foreign visits - any obvious recurrence of illness could end his chances of re-election. Otherwise, Buhari is profiting greatly from the benefits of incumbency in two main ways. First, there seems an implicit acknowledgement within the APC, which remains an uneasy coalition of disparate political groupings from the north and southwest, that a potentially divisive leadership challenge could damage the party electorally by demonstrating disunity and provoke defections back to the PDP, from whose ranks many APC members came. Second, there is a clear understanding - particularly after previous northern president Umaru Musa Yar'Adua died during his first term in 2009 - that the north's 'turn' in holding the presidency (Buhari's support base is in the north) should consist of two full terms to avoid provoking sectarian antagonism, meaning the APC would be highly unlikely to back a southwestern candidate this time round. Ambitious politicians from this region likely have their sights on 2023.

Buhari already seems to have ridden out a potentially damaging personal attack by two former presidents, Olusegun Obasanjo and Ibrahim Babangida, who in two separate open letters in January pointed out the widely acknowledged truth that Buhari's record so far is not only poor, but that he seems out of touch. Babangida called him an "analogue" president in a digital world. Such criticism does not appear to have harmed Buhari, even though his limited claims of success in tackling corruption and security matters have been further undermined, particularly with continued attacks by Islamist militant group Jamaat Ahl al-Sunnah li-Dawa wal-Jihad (widely known as Boko Haram) in the northeast, spiralling farmer-herdsmen violence in Middle Belt states, and a surge in killings by cattle-rustling bandits in the northwest.

A second term for Buhari would not bring any radical policy changes, but rather a renewed focus on agricultural development and infrastructure projects, especially rail, to continue diversification of the economy away from heavy dependence on hydrocarbons. A combination of capital controls, import bans, and agricultural support projects have led to major increases in output, particularly of rice and sugar, and especially within Buhari's core support base in the rural north. The government is trying to support this through improved transportation to ports and major markets to reduce costs and transportation time, with the emphasis on building sections of a new rail line between Lagos and Kano. Funding has been approved for the USD6.7-billion link between Ibadan and Abuja, while the Lagos-Ibadan section is already under construction.

A key risk indicator for a smooth passage to a second term for Buhari would be a visible and public decline in his health, and he remains particularly vulnerable to a challenge for the APC nomination if reports of illness begin circulating before the national conference in June. There is also a moderate risk that Buhari could provoke a revolt in the APC if he maintains his opposition to a new Electoral Bill, which seeks to change the orders of polls in 2019, placing the presidential election last, and is strongly supported by parliamentarians. Buhari has tried to veto the bill, but the validity of this is likely to be challenged by the Supreme Court.