The European Union is taking legal action against the United Kingdom, arguing that it does not respect the conditions of the Brexit withdrawal agreement and is violating international law. The 27-nation EU is objecting to Britain unilaterally extending a grace period beyond Apr. 1 that applies to trade on the island of Ireland, where the EU and the United Kingdom share a land border. A special trade system was set up as part of the Brexit divorce deal. It marks yet another worsening of relations between the two sides since a divorce transition period ended on Jan. 1.