Zimbabwe's so-called global political agreement, intended to achieve a coalition government between Morgan Tsvangirai and Robert Mugabe, was never worth the paper on which it was written.

Soon after the agreement was signed on 15 September last year, it became clear that it was not a matter of "if" but when it would all collapse. Even as the two leaders delivered their speeches at the signing ceremony, the philosophies of Tsvangirai and Mugabe were like oil and water. They simply cannot mix.

While the opposition leader, Mr Tsvangirai, was lucid on how Zimbabwe could pull back from the precipice, Mugabe did what he knows best: blaming Britain and everyone else except himself for all of Zimbabwe's past and future problems.

Download the new Independent Premium app Sharing the full story, not just the headlines

That the agreement has come down crashing before any attempt to implement it is not surprising. What is more surprising is why Mr Tsvangirai ever lent his signature to such a flawed arrangement in the first place.

Having experienced President Mugabe's crude tactics to keep him at bay over the years, Mr Tsvangirai ought to have known better. Investing any trust in his ruthless adversary through an outline document was never a workable option.

Now Mr Tsvangirai has given Mr Mugabe what he wanted on a silver platter; an excuse to blame the Movement for Democratic Change (MDC) leader - at least in the eyes of regional African leaders - for the failures of the agreement. It should have been obvious to Mr Tsvangirai that all his promises of adding flesh to the skeleton deal in a just and equitable way were not to be believed. It should also have been obvious to the MDC leader that Mr Mugabe's regional peers, who have stood by and watched while he destroys a once prosperous Zimbabwe, were never going to drop his support for him when the crunch time arrived.

The issues here are straightforward. Mr Mugabe is a callous and heartless dictator who is prepared to cling to power at all costs. He will never endorse a deal that effectively negotiates him out of power. Having lost the elections in March and shamelessly defied the will of the people, Mr Mugabe has effectively closed down the democratic process of achieving change in Zimbabwe. He thus is not going to be removed from power via democratic means.