The decision by President François Hollande of France to send troops to Mali to halt an advance by rebels with ties to Islamist extremists reprises a long tradition of French interventions in its former African colonies — and has bolstered the Socialist president’s previously flagging popularity.

The French move has been supported by the European Union, whose member states share French fears about the spread of radicalism across the Mediterranean. But it has superseded the bloc’s own ambitions to become a serious player in global affairs and still left the French to fight mostly on their own. The union is sending some military trainers.

Europe’s economic troubles, meanwhile, are far from over, with much of the Continent expected to be in recession this year. Even Germany seems to be losing momentum — its economy contracted by 0.5 percent in the final months of last year. Elsewhere, unemployment is soaring to levels that could threaten grave social unrest, with more than a quarter of working-age people in Greece and Spain without jobs.

But the European Union, widely criticized as not doing enough to raise employment, has been struggling to put even its own economic house in order after leaders failed in November to agree on a long-term budget for the 27-nation bloc. Leaders will take another swipe at this divisive issue early next month.

After being consumed for so long by efforts to salvage the euro zone, “leaders now think it is safe and are becoming perhaps too complacent,” said Charles Grant, director for the Center for European Reform, a London-based research unit. “The only time European leaders have agreed to take important steps is when there is a crisis. As soon as the crisis stops they relax.”

Germany, he said, has now backed away from tentative support for a change in the basic European Union treaties that could help the European Union forge common policies.

Already distracted by national elections next September, Germany could turn even more inward-looking as Chancellor Angela Merkel seeks to overcome her party’s defeat over the weekend in a down-to-the-wire state election in Lower Saxony. She remains the dominant figure in German and European affairs, but the surprise election setback has dented her aura of invincibility.