Gov. Martin O'Malley's intervention in the wage fight between Johns Hopkins Hospital and its service workers reflects the lingering dispute's significance but also signals that it may be resolved soon. The hospital and members of the 1199 SEIU United Healthcare Workers East labor union, which represents 2,000 Hopkins workers, went back to the bargaining table Tuesday after the governor asked them to take a cooling-off period. Union leaders also called off a four-day strike that was to have begun Friday. It would have been the second strike in the dispute. Workers walked off the job for three days in late April after negotiations for a new contract broke down. Talks began in March and have continued intermittently.