Germany has initiated random border checks with France, the Netherlands, Belgium, Luxembourg, and Denmark to curb irregular migration, expanding existing controls at borders with Poland, the Czech Republic, Austria, and Switzerland. These checks, scheduled for six months, follow recent extremist attacks. The move tests EU unity, as it challenges the Schengen free travel agreement. Trade unions worry about potential trade impacts, but a return to fully closed borders is not planned. German police acknowledge the difficulty in checking every vehicle due to the extensive borders.