"French education policies in Algeria and Vietnam present two illustrative examples. Both histories demonstrate a direct French administration reducing relatively well educated societies to illiteracy. John Ruedy proposes that the strong emphasis on scriptural reading and the high attendance rates at Koran schools probably developed a literacy rate among Algerians that even surpassed French levels at the time of the colonial power’s arrival. The French government replaced this traditional school system with Christian-parochial and public education schools for French expatriates, European settlers, and a few sons of Algerian notables. Alexis de Tocqueville lamented: “Around us the [Algerian] lights are going out… We have made Muslim society much poorer, more disorganized, more ignorant, and barbarous than it was before it knew us.
A similar sequence of events is seen in Vietnam. Precolonial Vietnam housed at least two schools in each district. Ngô Viñh Long estimates that pre-French-era rural literacy rates may have even surpassed urban literacy. David G. Marr estimates that up to 25 percent of Vietnamese could read enough characters to decipher basic contracts and other records. Yet by the mid-1920s, he bemoaned, it “seems unlikely… [that] more than five percent… could read a newspaper, proclamation, or letter in any language."
Mark Caprio, Japanese Assimilation Policies in Colonial Korea 1910-1945, pg 35-6
He then goes on to explain that the current Vietnamese alphabet, quoc ngo, was meant to function as a transition alphabet, to shift the Vietnamese population from their native language to full French. and look how that worked out!