We present a deterministic strongly polynomial algorithm that computes the
permanent of a, nonnegative nxn matrix to within a multiplicative factor of
e(n). To this end we develop the first strongly polynomial-time algorithm
for matrix scaling - an important nonlinear optimization problem with many
applications. Our work suggests a simple new (slow) polynomial time decisio
n algorithm for bipartite perfect matching, conceptually different from cla
ssical approaches.