DUBLIN — Before his recent resignation, outgoing Irish Prime Minister Bertie Ahern prefaced the annual St. Patrick”s Day pilgrimage to the White House by predicting “a hard year” ahead for the Irish economy. The banking crisis and credit crunch in the United States, as well as the falling dollar, worry Irish policy-makers. Ireland has 25 percent of its trade in dollars and has bet much of its recent economic boom on a 12 percent corporate tax rate — an enormous incentive for U.S. multinationals such as Intel and Microsoft to run pan-European operations out of Ireland. Google has the headquarters of its European and Middle East operations in Dublin. “The company is very pleased with how the Dublin operation continues to develop,” a Google spokesman said.