France-Italy dispute over Tunisian migrants (2011)
Italy gave temporary residence permits to thousands of Tunisians who arrived after the Arab Spring, letting them travel onward. France blocked trains from Italy at Ventimiglia, and the two governments clashed over Schengen rules.
France briefly halted rail traffic; both sides accused each other of breaking Schengen's spirit.
The row pushed the EU to revise the Schengen Borders Code and clarify when internal checks are allowed.
It is the closest precedent: two large Schengen members using border checks against each other over who bears the migration burden.
