But such bailouts are only stop-gap measures. Portugal and Spain, and to a lesser extent Belgium and Italy, remain vulnerable to pressure from bondholders. Portugal is likely to receive 50-100 billion euros over the next few months. But should Spain also need a bailout -- which could cost as much as 600 billion euros -- the 750 billion euro European Financial Stability Facility would soon be exhausted. In that event, the main euro creditors, primarily British, French, and German banks, might have to accept so-called haircuts, substantial cuts in the principals of their loans. (The banks' tax-avoidance strategies might inflate this total, but the Bank for International Settlements has estimated that the exposure of British, French, and German banks to the group of vulnerable debtor states referred to as the PIGS -- Portugal, Ireland, Greece, and Spain -- amounted to more than $1 trillion in mid-2010.) Encouraged by Germany, some of the states in difficulty have sought to placate bond markets by making ruthless cuts in government spending. But as many economists have pointed out, these measures are hindering growth without satisfying bondholders that their money is safe; bondholders worry that these measures are not politically sustainable. In fact, they are likely to undermine Europe's political union.