A Clarion Call

An unidentified virus is decimating the world. A highly ranked government scientist who had previously warned against such a potential peril is quick to recognize its virulence and the devastation it could cause. He convinces the president of the US to isolate all units of the Navy currently at sea and urgently trasfer equipment and scientists to these vessels to commence development of a cure.
The world is rapidly succumbing to the pandemic except for one city, the most isolated capital city in the world, where early advice enabled the government to close down all trasport links (rail, road, air and sea). This effectively quarantined the population, though not without some necessary harsh actions. Aware that this city could not maintain its unifected status without armed forces assistance, the US navy ships are ordered there immediately and placed under command of its government. This decision benefits the US fleet as they could not remain at sea for the duration required to develop a cure, so this secure land base was vital if mankind was to have a future.
Quick responses from the UK and France allowed some of their ships to set sail before they too were decimated. Although there are problems with their vessels they too join the US ships and place themselves under command of the local government.
The search for a cure is not the only priority, as many isolated communities around the world have made contact with the city seeking urgent assistance. Helping these people was of vital importance if mankind was to be saved. But anarchy reigned where survivors with a natural immunity to the virus had reverted to a dark ages mentality at an alarmingly rapid rate; gangs roamed the streets, taking what they wanted and raiding communities that had managed to isolate themselves from the plague.
Realising that when and if a cure is found, this city will be the most powerful force left in the world, the politics of the future must be decided...
Meanwhile, at city offices, the Premier of the state is desperately organizing an authority that supersedes all previous levels of government to overcome the bureaucratic quagmire that has arisen. Actions must be rapidly approved and carried out in this time of crisis, so to that end, and based mainly on a strong sense of perception, he appoints an unusual young man to this senior position.