New York drug maker Pfizer and Dublin-based Allergan have called off their proposed $160 billion merger, which would have headquartered the new company in Ireland to slash its U.S. tax bill. The deal collapsed days after the U.S. Treasury Department announced new steps to curb such tax-avoiding maneuvers, called “inversions.”

The outcome is “a major win for President Barack Obama, who has been pushing to curb deals in which companies move overseas to cut taxes,” Reuters reported.

Obama in Ireland in 2011.

For Ireland, the importance “is more in the signal it sends about the hardening international approach to multinational tax than in the specific implications from the collapse of the deal,” Cliff Taylor writes in The Irish Times. “It demonstrates again that the days of using tax as the main attraction for companies to locate here are coming to an end – and that there may well be significant implications for existing big Irish employers in the changes to come.”

The corporate tax rate in Ireland is 12.5 percent. In the U.S., business taxes range from 15 percent to nearly 40 percent. Northern Ireland plans to cut its business rate to 12.5 percent in 2018 to be more competitive with the Republic. But that’s now said to be threatened by Britain’s potential exit from the European Union in a June referendum.