The world economic crisis that, since 2008 has also struck the real economy, cannot be attributed only to the United States bubble which in 2007 involved the mortgage credit market, but it is the result of a series of factors among which the imbalance of the financial market, of the public accounts of the main economies and the real sector. Also agriculture, which has always been considered an anti-cyclic sector, has seen a strong slowdown with a plunge in the trade flows. This paper analyses the changes which happened to the competitive position in the world market of some Mediterranean countries and of France, Italy, Spain and Turkey in particular trying, moreover, to understand the vulnerability of the countries belonging to the EU concerning their integration into an economic and monetary union. The results show how much the crisis has involved all the countries bringing, on the whole, a reduction of the competitive potential in the international market which has been less strong in Turkey, the country characterized by a low per capita income and a low public debt. It can be seen, in particular, how the sectors with a strongest commercial specialization have showed a better resistance to the pressure of the recessive trend.