Steve Howell, Freshwater’s chief executive, writes a monthly column – Business Talk - for the Western Mail newspaper. The views expressed are Steve’s and not necessarily those of the company.

When Nelson Mandela formed South Africa’s first post-Apartheid government in 1994 about a quarter of its members had spent much of their lives in exile in London.

Since Ghana won independence in 1960, three of its presidents have been alumni of the London School of Economics, including Kwame Nkrumah, a man Mandela himself saw as iconic.

In the 1930s, Jomo Kenyatta, the founder of Kenya, studied at a Quaker college in Birmingham and at LSE and University College London.

Londoners – indeed everyone – should be proud of the positive connections between the UK capital and Africa. Most probably are, but there are other voices shouting loudly in the wake of the brutal murder of British soldier Lee Rigby who would have us think differently.

One notorious far right figure tweeted that ‘no stabbings in Woolwich would be news….since being swamped with Africans it’s – like Africa!’

In fact, crime in that part of London is around the average for the capital and has been going down in recent years.

But mud has a nasty habit of sticking – especially when some are actively exploiting the Woolwich stabbing to blame ‘Africans’, ‘Muslims’ or ‘immigrants’ for just about everything from unemployment to terrorism.

And the danger is they could drag all of us into the gutter with them, setting an agenda that could have grave economic consequences.

In the week of Gunner Rigby’s murder, the Office for National Statistics published immigration figures showing the number of foreign students arriving in Britain had dropped 22% in the year to 2012.

The Government boasted the figures showed they had ‘cut out abuse’ but Migration Matters – a cross-party group – said they ‘must not lose sight of the economic contribution migrants make’ at a time ‘when the economy needs as much stimulus as possible’.

Migrant Matters estimates the 22% drop, which equates to 56,000 fewer students, has cost the economy £725m.

According to the Government’s own estimates, the overall value to the UK economy of overseas students is £14bn per year – equivalent to 4p on the basic rate of income tax.

Discussing this with people in the Welsh university sector, it appears the sharp drop in enrolments from Asian and African countries is being driven by a perception they are not welcome here.

It is not a case of abuse being cut out, but rather many potential applicants opting not to come to a country where they fear they will be perceived as a problem or a threat.

You only have to give global growth statistics a cursory glance to see how serious this could be. The International Monetary Fund forecasts that seven of the world’s ten fastest-growing economies will be in Africa in the five year period from 2011 to 2015.

Ethiopia, Mozambique, Tanzania, Congo, Ghana, Zambia and Nigeria will have average annual growth rates ranging from 6.8% to 8.1%. Only China and India are forecast to have higher growth in the period.

And don’t kid yourself if you think this is just because Africa is coming from a low base. The absolute numbers are also impressive: in 2012, foreign direct investment in Africa totalled £45.8billion and bilateral trade with Africa was worth $1.17 trillion. The continent’s total Gross Domestic Product is set to break the $2 trillion mark this year.

Increasingly, Brazil, India and China are displacing the old colonial powers of Europe as Africa’s main economic partners. And within the continent, South Africa has become a powerhouse, ranking among the leading players as a source of investment for its neighbours.

We can ill-afford to ignore these changing realities. Wales played a big part in the worldwide movement against Apartheid. Only last year, Archbishop Desmond Tutu visited Cardiff.

We need not be tainted by this recent spate of hate-mongering against Africa, and it is good to see the Welsh Government’s programme of trade missions includes two events in South Africa this year: AfricaRail later this month and an international food exhibition in September.

Welsh universities are also active internationally, no doubt eager to find today’s would-be Nkrumahs and Kenyattas.

But is Africa on the radar of Welsh businesses? It should be – the bigotry of the far right is not only wrong, it’s economic madness.

Steve Howell is chief executive of Freshwater UK, the Cardiff-headquartered media group, and chairman of WalesWorldWide.org, an online networking platform for Welsh businesses. Follow him on Twitter: @SteveFreshwater