The stiff breeze that gusts through the winding streets of Geneva's Old Town to the swanky boulevards along the lake has taken on a bitter new chill. Switzerland, the country synonymous with discreet financial services for the rich, this month agreed to ease its legendary bank secrecy laws – and the country's private bankers fear their world will never be the same.

Bern's acceptance of international standards on tax transparency, potentially lifting the veil on billions of francs in foreign assets never declared by their owners, came in an international chain reaction by countries whose bank secrecy rules long appeared impregnable.

The process started with a growing US investigation into UBS, the world's biggest wealth manager, that endangered Switzerland's largest bank and prompted Bern into a panic decision to force the group to surrender up to 300 secret names to the US tax authorities.