One of the views most widely encountered in the literature on the Crimean War is that Austrian policy aimed at acquiring the Danubian Principalities in one form or another. Austria's purposes were not merely defensive, but expansionist. She wanted to replace the existing Russian protectorate by an exclusive protectorate of her own, to make herself the heir to the Ottoman Sultan's suzerain rights, and thereby pave the way to ultimate annexation. Or, if this proved impossible, she wanted at least to exercise an exclusive political influence in the Principalities, and to incorporate them permanently into her economic sphere and military system. The evidence for this view seems, on the surface, quite impressive. For Austria did force Russia to evacuate the Principalities by diplomatic ultimatum and military demonstration in the summer of 1854, and immediately moved in to occupy them herself. Her military commanders attempted to exclude the Turks from a share in the occupation, and failing this, tried to limit the Turkish role as much as possible. During the occupation, they interfered in matters of local administration and supported officials friendly to Austria against the wishes of the Turks and the local magnates. Austria also undertook the development of roads and a telegraph system, surveying, and other projects designed to aid her economic penetration of the territory. Her occupation was prolonged until 1857, and ended then only under heavy pressure from the Western Powers.