For much of the past two years, José Luis Rodríguez Zapatero has seemed to be able to walk on political water. In a gloomy European firmament dominated by tarnished leaders such as Tony Blair and Jacques Chirac, the star of Spain's young Socialist prime minister burned brightly. Now, he has stumbled, and his mettle will be tested in the way he picks himself up.

On December 29, Mr Zapatero told Spaniards with conviction how much better off they would be in a year's time, mentioning the peace process he was doggedly pursuing with Eta, the Basque separatist group. The following day a bomb exploded in the carpark at Madrid's Barajas airport, killing two Ecuadorean immigrants and ending a nine-month-long Eta ceasefire. Talks with the radical nationalists are, for the foreseeable future, over. The prime minister is in deep trouble.