Anglophone separatists have been fighting for recognition of Ambazonia — named after Ambas Bay in southern Cameroon, an 1800s-era settlement for freed slaves — for decades. But calls for secession have amplified significantly in recent months.

So far Cameroon’s government has refused to engage in meaningful dialogue with separatists, largely because it flat-out rejects losing territory. Anglophone regions contribute to the nation’s economy and include important palm oil and other agricultural production.

“It is not possible to sit around the table with groups who would like to take the nation and cleave the nation,” said Issa Tchiroma Bakary, Cameroon’s information minister.

“Secession,” he said, carefully emphasizing every word, “this shall never, ever take place.”

Cho Ayaba, commander in chief of Ambazonian Defense Forces, who delivers orders from his home abroad, is convinced a section of the United Nations Charter gives Ambazonia status as its own nation.

“We are at a very, very dangerous crossroads,” Mr. Ayaba said. “The absence of willingness on the part of Cameroon to negotiate itself out of its occupation of Ambazonia and insistence on the utilization of disproportionate force leaves the Ambazonian people with no other choice than to defend themselves.”

English-speaking citizens of Cameroon make up about a fifth of the population in two of the nation’s 10 regions. Modern-day Cameroon is one of the most geographically, ethnically and linguistically diverse countries on the continent, so much so that it is known as “Little Africa.” But its two official languages, French and English, come from colonization.

Many Anglophones have long felt ignored by the French-speaking government, a sentiment dating to the post-World War I era when the League of Nations appointed France and England as joint trustees of what was then German Kamerun. The colonialists pushed their own cultures, languages, and legal and educational systems on their territories.