The tight circle of "securocrats", who sit on the Joint Operations Command (JOC) committee, are now believed to be in day-to-day charge of Zimbabwe's government.
They ensured Mr Mugabe did not step down after his defeat in the presidential election's first round in March and are now masterminding a campaign of terror to suppress the opposition Movement for Democratic Change and guarantee victory for Mr Mugabe in the June 27 run-off.
The government indefinitely suspended all work by aid groups and non-governmental organisations, accusing them of breaching their terms of registration.
Mr Mugabe is a useful figurehead who still commands the deference of other African leaders, notably President Thabo Mbeki of South Africa.
But the western diplomat said Mr Mugabe's power had ebbed away and Zimbabwe was now run by a "junta".
"This is a military coup by stealth," he said. "There are no tanks on people's lawns, but the Joint Operations Command runs this country."
Read the whole thing here.
This is not good news; not good at all. The two best hopes for Zimbabwe were that Mugabe would retire and thus open the way for democratic reform or alternatively that a coup would remove him from office. Well, it now appears that the "quiet coup" is what is keeping the mad old monster in office. Now it seems that not ieven the death of Mugabe will end the horror that has been visited on his country in recent years.