But the whole idea of zionism was and is to established a nominally Jewish state free from Torah and Mitsvos. And the IDF is part of the state. To create an IDF that is not anti-Torah, one needs to create a non-zionist medinah.
Note that in the United States, if some was prejudiced against Blacks or Hispanics (and note that frum Jews are a higher percentage of the Israeli population than Blacks or Hispanics are of the American population), the prejudiced person would be considered unacceptable to serve as an officer in the military, and probably would be largely excluded from any form of public service such as a member of the legislature. If Israel, including the IDF, were to give up zionism, the entire elite of society, and his includes those who run all government agencies, and especially the army, would be excluded. This is highly unlikely to happen. No matter how much the Religious zionist (and Modern Orthodox) yearn for Jewish state in which religious Jews are not discriminated against, those who rule Eretz Yisrael years for a state in which religious Jews are not present.