Tax heavens have long been a topic neglected by researchers and not much broached by political leaders. Yet they play a linchpin role among the cogs of globalization. The subprime crisis has highlighted their harmful role, particularly due to the fact that they make it easier to conceal financial risks. Thus, regulating tax havens has become one of the priorities for the G20 in 2009. The G20’s first decisions are significant but it will undoubtedly be adequate to go further, despite the pressures exerted by private actors benefitting from tax havens. The year 2009 may have paved the way for greater transparency in the international financial system, but 2010 will be a key year to prove the political will to include, or discard, attempts at regulation over the long term.