"Commander-in-chief [President Jacob Zuma] has not lifted a finger to address [the] dire situation of soldiers, nor even taken the time to visit their bases … to listen to their problems, concerns and frustrations," said Sandu national secretary JG Greef.
In August 2009, more than 1 000 soldiers defied a military and court order and embarked on a wage protest at the Union Buildings in Pretoria.
The defence department accused the soldiers of failing to obey orders and failing to dissociate themselves from a violent protest and mutiny.
Last week, the Supreme Court of Appeal ruled in favour of the department and internal disciplinary proceedings began.
Greef said the situation of soldiers had deteriorated since then.
"It is little wonder therefore that some soldiers would rather trust Mr Malema to at least listen to their concerns, rather than trust their own commander-in-chief, the president."
The situation within the military required decisive leadership, he said.
Gareth Newham, head of the crime and justice programme at the Institute for Security Studies, said Malema appeared to be exploiting the perceived "leadership vacuum".
Malema's recent visits to mines, where he encouraged workers to embark on a national strike, and his planned meeting with soldiers in Lenasia later on Wednesday, were part of his broader political agenda.
"I think he is trying to show support for [deputy president Kgalema] Motlanthe [ahead of the Mangaung elective conference].
"He is trying to send the message that Zuma is not providing sufficient leadership."
It appeared he was trying to show that he was providing leadership "on the ground".
"He can say, even our soldiers invited me to speak to them; Zuma is not looking after soldiers and he [Malema] is stepping into that leadership vacuum."
As soldiers represented state security, Malema's intention to address them – taking into account his frequent attempts to incite workers against their employers – could make for a volatile situation.
"He is trying to provoke Zuma, to paint himself as a victim of persecution – like Zuma did against [former president Thabo] Mbeki.
"Zuma is probably reluctant to take action against him for this very reason," Newham said.
Malema would likely use his meeting with the South African National Defence Force to signal that "he is more dangerous outside the ANC than he is in the ANC".
It appeared that Malema was trying to get back into the ANC, from which he was expelled in April."
"You will notice, he doesn't attack the ANC itself, but specific people within the organisation," Newham said.
The focus of his verbal attacks were often Zuma, and national executive committee member Cyril Ramaphosa, who chaired the National Disciplinary Committee of Appeal which finalised Malema's expulsion from the party.
Last month, Malema called for the resignation of Zuma and Police Minister Nathi Mthethwa in the wake of the violence at Lonmin's Marikana mine, in which 34 people were killed on August 16.
"President Zuma decided over the massacre of our people [sic], he must step down," Malema said at Wonderkop.
He also claimed that the reason the police shot at the miners was that they were trying to protect the interests of Ramaphosa, who, he alleged, owned shares in Lonmin. – Sapa