By Barnaby Mason
BBC diplomatic correspondent, Abuja
The Zimbabwean Government's announcement that it was leaving the Commonwealth followed hard on the heels of the body's decision that Zimbabwe would stay suspended until there was enough progress on the issue of democracy and human rights.
Mugabe has made the Commonwealth strategy irrelevant
A spokesman for the Commonwealth Secretariat said they were very disappointed by Zimbabwe's move.
President Robert Mugabe had threatened several times to pull Zimbabwe out of the Commonwealth.
Having its suspension extended indefinitely was the last straw and that was the essential point of the carefully worded statement put out after two days of argument at the summit in Abuja.
Mr Mugabe seized on it at once. In doing so he wrecked the Commonwealth leaders' strategy for encouraging and facilitating Zimbabwe's early return to full membership.
The strategy now looks irrelevant. Mr Mugabe's move also suggests that reconciliation between the ruling and opposition parties in Zimbabwe is even more unlikely.
Obasanjo (r) stressed reconciliation as the key to progress
Reconciliation was stressed as the key to progress by the Nigerian chairman of the Commonwealth, President Obasanjo.
It now looks improbable that Zimbabwe could ever rejoin the Commonwealth while Mr Mugabe is in power.
Some may even raise the question of whether some of its southern African neighbours might be tempted to leave the organisation themselves.
It is unlikely, but South Africa, Mozambique, Zambia and Namibia are deeply unhappy with the outcome of the summit.
For others, including Britain, Australia, Canada, New Zealand, it was vital to send the message that the Commonwealth is serious about member states observing democratic principals.
Mr Mugabe's angry reaction, they will say, proves in fact that the Commonwealth matters.