How did Omar Bongo establish a single-party system in Gabon?

Omar Bongo established a single-party system in Gabon in 1968, the year following his rise to the presidency upon the death of his predecessor, Léon M’ba.12

The foundation for this regime was laid after a 1964 military rebellion against M’ba—who had attempted to institute a single-party state—was suppressed by French forces. This intervention secured the political environment that facilitated Bongo’s eventual ascent. Under his leadership, the Gabonese Democratic Party (Parti Démocratique Gabonais; PDG) became the sole legal political party in the country. This single-party system remained in place until 1990, when popular unrest and economic pressures forced the government to adopt constitutional amendments that restored a multiparty system.12