Speaking after a meeting with Olusegun Obasanjo, the retired general who will be Nigeria's first civilian ruler in 15 years, Mr Cook pledged Britain's support for Nigeria's new political era. "There are still two months in which things can go wrong," he said, "but I'm hopeful they won't go wrong."
As a precaution, he announced pounds 750,000 of aid to help to restructure the Nigerian military, which still looms in the background, however discredited the army was in power.
These weeks at his estate here, where he farms cassava, maize, and livestock, will be General Obasanjo's last spell of relative tranquillity before he takes over the country that has the potential and resources to be a regional superpower but which has been brought to its knees by economic mismanagement.
Nigeria has almost $30bn (pounds 18.5bn) of official debt, with little hope of a rescheduling deal with its main creditor countries until it reaches a monitoring agreement with the International Monetary Fund. This would place the IMF's seal of approval on more rigorous policies.
"The IMF will want to see that this new government behaves differently," Mr Cook warned after his meeting with the general. "They will want to see some progress towards tackling arrears before rescheduling."
This will be rendered all the more painful and difficult by the fall in the oil price, which accounts for more than 80 per cent of government revenue. Although this year's budget has been based on oil at $9 a barrel, some analysts predict the price could fall to $7 or under.
Then there are Nigeria's chronic problems of epic corruption, unliveable- in cities, and deep ethnic unrest - epitomised by kidnappings of oil industry workers in the Niger delta, where the inhabitants are mired in desperate poverty.
The key foreign policy issue facing General Obasanjo will be Sierra Leone, whose government is only kept in power by the Nigerian-led Ecomog West African military force. He promised that Nigeria would remain loyal to Sierra Leone and that "we won't just pull out and abandon them".Reuse content