 Complete the following phrase:  German forces also operated in the Battle of Jarama, which began with a Nationalist offensive on 6 February 1937. It included German-supplied ground forces, including two batteries of machine guns, a tank division, and the Condor Legions anti-aircraft guns. Bombing by both Republican and Nationalist aircraft, including Ju 52s from the Legion, helped ensure a stalemate. It showed up the inadequacy of the Legions aircraft, faced with superior Soviet-made fighters. Von Thoma requested Irish nationalist support for a tank advance at one point, never to be replicated. Use of He 51 and Ju 52s, and the Legions anti-aircraft guns used in ground roles, only partly mitigated what was a significant defeat for the Nationalists at the 