  We classify Lie 3-algebras possessing an invariant lorentzian inner product.
The indecomposable objects are in one-to-one correspondence with compact real
forms of metric semisimple Lie algebras. We analyse the moduli space of
classical vacua of the Bagger-Lambert theory corresponding to these Lie
3-algebras. We establish a one-to-one correspondence between one branch of the
moduli space and compact riemannian symmetric spaces. We analyse the asymptotic
behaviour of the moduli space and identify a large class of models with moduli
branches exhibiting the desired N^{3/2} behaviour.
