Historians by the 1930s saw the Second Empire as a precursor of fascism, but by the 1950s were celebrating it as leading example of a modernizing regime. However, historians have generally given Napoleon negative evaluations on his foreign policy, and somewhat more positive evaluations of his domestic policies, especially after he liberalized his rule after 1858. His greatest achievements came in material improvements, in the form of a grand railway network that facilitated commerce and tied the nation together and centered it on Paris. He is given high credits for the rebuilding of Paris with broad boulevards, striking public buildings, and very attractive residential districts for upscale Parisians. He promoted French business and exports. In international policy, he tried to emulate his uncle, with numerous imperial ventures around the world, as well as wars in Europe. He badly mishandled the threat from Prussia and found himself without allies in the face of overwhelming force.