Whakaotihia te rerenga e whai ake nei: I muri i Congo-Brazzaville, i mahi a Mondjo hei rangatira ope taua, a ko ia te Kaiwhakahaere o nga Akoranga me nga Akoranga i te Marien Ngouabi Military Academy i Brazzaville mai i te 1987 ki te 1993. I tū ia ki te taha o te kaiārahi whakakeke a Denis Sassou Nguesso i te wā o te
Hune-Oketopa 1997 pakanga ā-iwi; ka mutu te pakanga ki te hokinga mai o Sassou Nguesso ki te mana me te whakakore i te Perehitini Pascal Lissouba. I te marama o Tihema 1997, i tohua a Mondjo hei Kaihauturu mo te Rohe hoia 1, kei roto i te taone nui o te whenua, Pointe-Noire; i noho ia i taua tuunga mo nga tau e rima. I tohua ia hei Tumuaki o te Kaimahi o nga Rererangi Congolese i te 20 o Tihema 2002, a ka whakatairangahia ia ki te taumata o te rangatira nui ("général de division").