If you use the rudder alone and don't touch any other control, the jet will start banking + turning in the direction of rudder input. This is due to increased lift on the swept back wing that is now meeting the air at a more perpendicular angle + earlier separation on the "inside wing". A turn without banking and pulling is however very ineffective in a fighter and hardly ever used.

If you force the wings level with rudder input the jet will side slip, but for most cases also turn a bit, just not very effectively.