Tony Blair has made a name for himself as the scourge of distant dictators, from Slobodan Milosevic to Saddam Hussein. At the drop of a hat, British squaddies are dispatched to fight and die in remote troublespots.

But what are the British, possessors of a splendid-sounding ethical foreign policy, doing to save millions of Zimbabweans from the dictator whose latest infamy, during a time of drought and famine, is to starve anyone who hasn’t voted for him?

Not a lot.

Which is strange, when you think about it. Zimbabwe, as Southern Rhodesia, was a British colony. The deal that ended a war between its separatist white settlers and its black majority was struck in 1979 with British help. Zimbabwe’s legal system is modelled on Britain’s, with lashings of horsehair wigs and woolsacks. Lots of Zimbabweans, especially whites, still have British passports. And British diplomats have repeatedly tried (and failed) to help to settle the agricultural ownership problems from which today’s crisis stems.

So Britain has more shared post-colonial history with Zimbabwe than with any of the places Tony Blair is so enthusiastic about biffing. That should be reason enough to make a priority of helping the Zimbabweans in their hour of need.

And if ever there was one, this is such a time. The whole of southern Africa is hungry. But the situation in Zimbabwe is especially dangerous. This isn’t just because, by next March, there will be enough food for only half the 13 million population. It’s because Robert Mugabe’s Zanu (PF) party bosses are already sending food only to those whose political loyalty can be proved. Matabeleland, where the ethnic minority lives, is going in fear. And so are plenty of others. When the food trucks trundle in, if you can’t show a Zanu (PF) card, you starve.

This is only the latest Kafkaesque policy from a regime whose crimes have gone unpunished for so long that it feels invincible. Elections are stolen. Opposition leaders are tortured and terrorised. Big commercial farmers have been kicked off their land without compensation. And, saddest of all, half a million dispossessed black farmworkers are now joining the ranks of the starving.

While Britain stands by, wringing its hands, others at least are getting angry. The World Food Programme suspended relief distribution in part of Zimbabwe after Zanu (PF) thugs “liberated” three tons of food last month. The European Union has condemned Zimbabwe for using food as a weapon against its people.

And Washington is so concerned about the six million Zimbabweans threatened by famine that US officials are suggesting “very intrusive interventionist measures” to get food aid in. That is no bad thing. Even people who usually feel uneasy about America playing global policeman will agree that a country whose President is unhinged enough to object to foreign food aid during a famine needs outsiders to muscle in with airlifts of peanut butter mercy parcels.

But where are the British shortbread biscuit love-bombs? And where is the tough British diplomacy needed to rein in Mugabe? What about asking the Zimbabwean High Commissioner to leave, for example, or broadening visa restrictions on Zimbabweans, or working harder at freezing Zanu (PF’s) foreign assets, or tabling a resolution on Zimbabwe at the UN Security Council?

We’ve relied for too long on the vain hope that South Africa would do the dirty work of licking Zimbabwe into shape (however obvious it was that Thabo Mbeki was going to disappoint). A Foreign Office line now is that Britain should work tactfully behind the scenes, nudging other states into protesting rather than openly confronting a touchy former colonial subject itself.

It’s all strangely timid when compared to Britain’s posturing on other continents. Yet this is no time for post-colonial cowardice. A bad man can still be bad even if he’s a black former imperial subject. If Tony Blair wants to fight the good fight, Zimbabwe is a good place to start.