Germany's Defence Minister, Peter Struck, has rejected claims that anti-Semitism is widespread in the military.
Guenzel is an 'isolated case' the defence ministry says
Mr Struck on Tuesday sacked the head of Germany's special forces after he voiced support for an MP who has been accused of holding anti-Semitic views.
Some MPs are concerned that General Reinhard Guenzel's attitude is not isolated among military personnel and have called for an investigation.
But Mr Struck said that the military was "rooted in democracy".
Mr Guenzel had written to the Christian Democrat MP Martin Hohmann praising his "courage" for making a speech which has sparked national controversy, by comparing the actions of Jews in the 1917 Russian revolution with those of the Nazis.
Rainer Arnold, a Social Democrat member of the parliamentary defence committee, said: "It must be urgently investigated how a person with this kind of mentality can become brigadier general - especially in the elite forces."
A group representing serving and former officers called on Mr Struck to improve political education in the armed forces and to make promotions dependent on "democratic behaviour".
"The army is not right-wing and undemocratic per se but a significant proportion of soldiers in leadership positions lack democratic awareness and commitment," said Helmuth Priess, spokesman for the Ak Darmstaedter Signal group.
But Mr Struck said soldiers are taught about Germany's Nazi past and there are regular studies of soldiers' attitudes.
"I am completely convinced that members of the armed forces and especially the KSK (elite forces), are firmly rooted in democracy," he said.
"I have no reason to assume the general's views are shared - quite the contrary."
Party under pressure
The head of Germany's Jewish community, Paul Spiegel, praised Mr Struck for his swift decision to sack Mr Guenzel.
But he called on the opposition Christian Democrats to distance themselves from Mr Hohmann.
The party has removed the MP from two committees but party leader Angela Merkel is under pressure to expel him.
German prosecutors have launched an investigation into Mr Hohmann's speech after a criminal complaint was filed against him.
Mr Hohmann has apologised for his comments, saying that neither Germans nor Jews should be considered perpetrators of atrocities.