ROME — After 14 months of bickering, Italy’s government collapsed on Tuesday, plunging a key European nation already hobbled by financial fragility and political chaos into a renewed period of crisis and uncertainty.

During the government’s short tenure, the nationalist-populist coalition struck fear into the heart of the European establishment. It antagonized the European Union, flouted its budgetary laws, demonized migrants and embraced President Vladimir V. Putin’s Russia and his strongman politics.

[Update: Italy’s new government takes shape, sidelining Salvini and the hard right.]

But any relief could be short-lived among critics who have accused the government of isolating and weakening Italy as it drastically reoriented the country’s place in Europe.

The government coalition of the hard-right, anti-migrant League party and the anti-establishment Five Star Movement came apart after a mutinous power play by Matteo Salvini, the League leader and the country’s increasingly popular interior minister.