I agree with stopstart in a way but the Congo is not a British problem, it is a mainland European problem because the Belgians ran it before, not the Brits.
Zimbabwe is a different kettle of fish. As an ex-Rhodesian who has known friends of all colours murdered I know that they need all the help they can get but military action is not the answer. The situation, however you dress it up, is not the same.
In all African countries plus a lot more in the Far East, Central and South America a considerable amount of the country's wealth ends up in foreign bank accounts or property and Zimbabwe is no exception. Should the West take on Zimbabwe then it would be the first of a long list.
Nigeria has been a major oil exporter for decades yet the vast majority of its population are on the breadline, the same for Venezuela and Indonesia. Advanced Middle Eastern coutries are entirely dependant on what the leader decides to hand out. Democracy and accountability as we know it are non-existent.
The United Kingdom has been fortunate in that the various tribes have been seperated by national borders with the unfortunate exception of Northern Ireland. Europe has been dissected and re-assembled for centuries and its history is full of massacres of people in the wrong place at the wrong time. National boundaries in Africa were imposed by the colonialists and cut across innumerable tribal boundaries. It is too easy for a corrupt government to pass the blame for their shortcomings onto another tribe within their jurisdiction.
You can send as many peacekeepers and spent as much money as you like for years and when it stops you can pat yourself on the back. But unless you change the way the countries are run then as soon as you walk out it will start all over again.