On 21 August 2009, the Swiss government handed over the names of 4,500 American tax evaders to the US Congress, ending the legendary principle of secrecy on which the country’s banks had built their reputation for almost a century. How did the United States manage to force Switzerland to comply? One of the world’s biggest tax havens, the country had until now remained unreceptive to demands for greater transparency from around the globe. Why did UBS – the global leader in private fortune management – decide to waive its clients’ anonymity? The Birkenfeld scandal, named after the American banker who denounced UBS’s practices, led to an economic and political war between the mighty of America and Switzerland. UBS, exposed as inciting tax evasion on US territory, had been caught in a trap and dragged Switzerland down with it. Bankers, lawyers and politicians, all directly involved in this scandal of seismic proportions, recount the end of Swiss banking secrecy and the worries that now grip the country.