In 1976, when Robert Mugabe was still an unknown guerilla leader in much of Europe, he gave a rousing speech in Geneva which gave theoretical coherence to chimurenga, Shona for revolutionary struggle, which as the head of the Zanu-PF's liberation movement he was spearheading.

"Our votes must go together with our guns. After all, any vote we shall have shall have been the product of the gun. The gun which produces the vote should remain its security officer - its guarantor. The people's votes and the people's guns are always inseparable twins," he said.

Four decades later, the 1976 speech has now acquired the rings of a prophecy.

This after a silent coup which started with a grumbling statement on Monday by Zimbabwe Defence Forces head General Constantino Chiwenga announcing the army's displeasure at the purges in the ruling party and country - which had resulted in Emmerson Mnangagwa, vice president and heir apparent, being fired last week - and which escalated on Wednesday with army tanks parked on key Harare streets and buildings, culminating with Mugabe's house arrest at his palace.

In the final analysis, as it became clear Mugabe was unwilling to hand over power to another gun-toting veteran of that war in favour of his wife Grace, it was the army that decided to pull out guns from the national armoury to become the arbiter of the bitter succession fight.

The struggle to succeed the 94-year-old president had on side Grace Mugabe, an ambitious woman who had been plucked in the 1980s from the anonymity of the presidential typing pool to become first lady, and her faction against Emmerson Mnangagwa, a battle-hardened politician who was in prison with Mugabe in the 1960s and who in the 1970s became his personal assistant.

Naturally, when the army had to choose who would succeed Mugabe, it was Mnangagwa they opted for even though he never saw active combat in the 1970s war which forced Ian Smith to go to Lancaster House to negotiate Southern Rhodesia - now Zimbabwe - independence from Britain which came in 1980.

Why Mugabe, a suave political operator, theorist and survivor, had not seen how his words from the 1970s would come back to gnaw at him is a question that will occupy historians and political scientists for a long time to come.

Maybe it was the overweening influence of his wife Grace, born in 1965, to whom, as an old man of 94, he was increasingly reliant for his daily needs.

Maybe it was his dependence on Jonathan Moyo, a Rasputian political science scholar who turned from Mugabe's biggest critic in the 1990s into his arch-apologist and information tzar - he is accused by his enemies of saying the only way to destroy Zanu-PF is from within the party itself.

By turning to his wife Grace and to people like Jonathan Moyo, who was in Zanu-PF's guerilla camps of Tanzania for a while before he left for his studies in the United States and which act is interpreted by his enemies in the army as desertion), Mugabe forgot the compact of the vote and the gun which he eloquently spoken about then.

But, as in the statement by Chiwenga, Mugabe the person had become a liability to the military-nationalist-patriarchy project for the war veterans of that struggle to rule forever.

The country barely functions: most of what Zimbabwe uses, including milk, is imported; for over a year the country has been experiencing cash shortages because of a big import bill; unemployment is endemic and, as a result, millions of young Zimbabweans have crossed the border into South Africa, Botswana and other neighbouring countries to work in most cases as undocumented migrants.

As you and I are able to judge, the people no longer appreciate empty slogans and hollow speeches. They want us to talk about things that are meant to improve or sustain lives President Robert Mugabe, 1992

In 1992, a senior official from the ruling Zanu-PF said: "As you and I are able to judge, the people no longer appreciate empty slogans and hollow speeches. They want us to talk about things that are meant to improve or sustain lives."

The official who said this is Mugabe and yet in his autumn years, so nonchalant and removed was the man from what ailed the average Zimbabwean. He continued to live as if Zimbabwe was the second most important regional economic powerhouse after South Africa that it was back in the 1980s and 1990s.

He never missed a chance to fly to any conference - including to conferences on oceans, an absurdity for a land-locked country - to which he was invited.

The most recent egregious instance of this was in September when the Zimbabwean delegation to the United Nations conference had around 70 people and included people who had no government business being in New York, including his daughter Bona and her husband, Mugabe's playboy son Chatunga and other hangers-on who are paid daily allowances from the dwindling coffers of a state which every month struggles to pay its workers.

"There are some who from day to day get into the office, take off their jackets, take a piece of paper, perhaps write one or two things, take a newspaper and start reading. When they put their jackets down, it's tea time. I am not satisfied that everyone is doing a good [day]'s work," Mugabe said in 1992.

Mnangagwa: A savvy political operator resented by Mugabe

Mugabe had become that person who was anathema to him back then. He was always travelling abroad and had a laissez-faire approach to the business of governing and was perpetually fanning factional fights in Zanu-PF to perpetuate his rule.

Mnangagwa, a business-savvy political operator, realised that Zimbabwe's endless isolation was unsustainable and costing the country, after all, Zimbabwe isn't the only country in the world with diamonds, gold and other natural resources.

"You cannot say there are areas of our economy which we are happy with, infrastructure we are behind by 15 to 16 years, agricultural development the same, manufacturing; in fact capacity utilisation in some areas of our industry is down to 20 percent, so again, we have to retool by acquiring new machinery, technology and machinery so that we are competitive," he told a reporter while on a visit to China in 2015. "We have to see how we can create an investment environment which will attract the flow of capital. We must know that investment can only go where it makes a return so we must make sure we create an environment where investors are happy to put their money because there is a return."

For trying to reach out to the Chinese, the British and the international community, he earned Mugabe's resentment.

Mnangagwa had become a danger to Mugabe, who in Shona fits the noun "mbimbindoga", that person who stays on his own, fetishes the self and relies only on his counsel. Mugabe wanted his endless autumn of the patriarch to continue uninterrupted.

Russian poet Joseph Brodsky wrote, "the average length of a good tyranny is a decade and half, two decades at most. When it's more than that, it inevitably slips into a monstrosity."

It's not a surprise that it was ultimately the gun which Mugabe had spoken so approvingly of in 1976 which, ultimately, intervened to stop Mugabe's 37-year reign that had turned into a monstrosity from continuing any further.

Follow Percy Zvomuya on Twitter: @percyzvomuya