On Thursday morning in Davos, the Financial Times co-hosted a breakfast with HSBC to discuss emerging markets. As the guests gathered round the croissants, however, one speaker was missing: Youssef Boutros Ghali, finance minister of Egypt, had to withdraw at the last minute due to “unexpected” events.

It was a telling metaphor, not just for the 2,500-odd delegates at this year’s World Economic Forum, but for global investors too. When the WEF holds its annual meeting in Davos, the programme is planned with seemingly-clear ideas about the big themes of the day. This year, for example, the hot topics were supposed to include food security, financial reform and the euro; and, of course, the impressive rise of the emerging markets, which are now generating so much optimism among Western investors and businesses.

Yet, most years at Davos something unexpectedly throws a spanner in the planning works; this year, the issue being furtively debated in the corridors – albeit barely mentioned in the official programme – is the political turmoil afoot in Tunisia and Egypt.