The leader knows he only needs about 1/8 the people he has now, this is the easiest way to get there.
And he has made statments to this effect.
Zimbabwe's leadership takes lessons from the North Korean regime, which also allowed starvation to decimate its population in the 1990s.
The North Koreans were an early supporter of Mugabe's regime; there were State visits, "technological help", military training of the re-formed Zimbabwee Army (which so failed that the British, the hated "colonzers", were asked to come in and complete the job).Mugabe belongs in the next tier down from the Axis of Evil, only because he does not threaten anyone but his own population.
He is truly an Evil Man.