BRUSSELS—The plans European Union officials unveiled on Thursday for a new €100 billion ($110 billion) job-support program for members hardest hit by the coronavirus is the kind of tangible aid it needs to underpin crumbling economies—and to show its 446 million citizens Brussels can deliver in a crisis.

The bloc got off to a bad start as the virus spread last month. EU countries unilaterally shut borders and hoarded vital medical gear, leaving people stranded far from home, grocery stores struggling to stock shelves and hospitals desperate to save critically ill patients.

When Italy and Spain, reeling from some of the world’s most deadly outbreaks, urged their richer and healthier northern neighbors to help, Dutch politicians brushed off the appeals as new signs of southerners’ mismanagement.

The disputes reopened rifts from recent crises—over money between north and south, and between east and west over the rule of law.

EU officials belatedly shifted into overdrive. Over the past two weeks they have helped reopen borders, ship equipment to hospitals, send stranded citizens home and keep goods moving. The European Commission, the EU’s executive arm, suspended state-aid rules and waved through hundreds of billions of euros in government support to business.