Confining strings

We propose a hypothesis that all gauge theories are equivalent to a certain non-standard string theory. Different gauge groups are accounted for by weights ascribed to the world-sheets of different topologies. The hypothesis is checked in the case of the compact abelian theories, where we show how condensing monopole-instanton fields are reproduced by the summation over surfaces. In the non-abelian case we prove that the loop equations are satisfied modulo contact terms. The structure of these terms unfortunately remains undetermined.