Dutch elections rarely stir much excitement abroad, but the voting in the Netherlands Wednesday marks an exception. The big winner was Geert Wilders, a veteran right-wing campaigner, and the freakout his victory has triggered across Europe is something to behold.

Mr. Wilders’s Freedom Party (PVV) won a plurality of 37 seats in the 150-seat legislature. His next nearest competitor, a Labor-Green coalition led by Frans Timmermans, won 25 seats. Politicians will now negotiate to form a governing coalition, a process that often takes months in the Netherlands’ highly fragmented electoral system, and Mr. Wilders may not emerge as prime minister. But voters have sent a clear message.