Two-dimensional shear Alfven-wave turbulence is investigated for a pla
sma with arbitrary beta value. A set of three equations, which reduces
to the derivative nonlinear Schrodinger equation in the limit of para
llel propagation, is derived. The genuinely two-dimensional case is go
verned by two coupled equations. For a non-parallel one-dimensional sp
ace dependence, the nonlinearity is shown to vanish to all orders.