Sovereignty trumps contractual obligations every time. If the African countries that are leasing their land fall into difficulties in feeding their own populations, as they are likely to do if world grain prices rise sharply, the first resource they will turn to is the foreign plantations on their territory.

Essentially, the Middle East is left with two choices. “The region has to import. The question is, invest abroad or rely on the free market?” said Dr Eckart Woertz, program manager in economics at the Gulf Research Center in Dubai.