This probally could not happen ,but could Monaco become more powerful in any way?
My take, ASBish even though it may be...
1991 - Following the dissolution of the Soviet Union, an impoverished younger researcher from a secret Siberian laboratory "misplaces" a sample of a highly contagious and deadly airborne virus, sells it to an unknown foreign operative.
1992 - a multinational company/ a terrorist organisation (is there really a difference?) begins limited tests with the virus strain, not aware of its true capabilities
1993 - safeguards fail, a local worker of the testing center in Uruguay has become a carrier of the virus and infects his family and friends
1994 - the highly deadly Blue Plague (as it is called) spreads in South America; 90% of those infected will die within three weeks
1995 - first infection in the US is diagnosed in February
1996 - global chaos ensues. People attempt to flee the Americas to anywhere they can. Asian and European governments soon close their borders, but it will be of no consequense. By March, the Plague manifests itself in Beijing, Hyderabad, London and Valencia.
1997 - Scientists in Europe, Asia and Africa work feverishly to unravel the mystery of the virus, while in America all public order and governmental organizations have already collapsed following the deathly path of the Plague
1998 - After finally connecting the origins of the Blue Plague Virus with former Soviet research, Jean Malaparte, an epidemiologist in the University of Nice/Sophia Antipolis manages to find a vaccine that will protect 85% of those who receive it from succumbing to the virus.
Most of France has already collapsed into anarchy, however, and before getting the word of his discovery out Malaparte has to flee his laboratory to avoid being captured by a rampaging Obscurantist mob bent on destroying everything associated with modern science (which people, quite rightly too, blame for the virus).
Malaparte, with a few associates and his precious vaccine samples, flees towards Monaco, where rumours say some vestiges of order still remain. The Prince of Monaco has ordered his small state into a virtual lockdown, and a careful quarantine has been holding the Plague at bay for some time. With difficulty, Malaparte reaches Monaco and convinces a captain of the ad hoc-forces holding the perimer to allow him in. He gets an audience with the Prince.
Before too long, the people in Monaco are being vaccinated against the Plague and attempts are made to spread news of the cure to other surviving centres. Survivors from different parts of Europe start gravitating towards the rumored safe haven in Monaco. In the small city state, at least for now, civilization will survive.
Present day: After approximately 93% of humanity has been wiped out by the Blue Plague, anarchy rules pre-eminent. Only a few centres of pre-Plague civilization exist anywhere in the world. The Principality of Monaco (and associated territories) is the leading centre of order and power in Europe and the Mediterranian area, only rivalled by the island state of Malta. Contacts with the Americas or East Asia are virtually nonexistent.