The development of English into the world's lingua franca suggests that spelling is not an insuperable barrier.

ECONOMIST: The conflict in Georgia

The presence of the toxic Mr Lieberman in the foreign ministry is not itself an insuperable barrier to negotiation.

ECONOMIST: Israel's new government

In years past Turkey's spotty democracy was often cited to prove a negative: the Turkish case (along with Indonesia's and Malaysia's, also with reservations) showed that Islam did not pose an insuperable barrier to multiparty democracy.

ECONOMIST: The Turkish model