The heavy casualties inflicted on Chiang's own military strength forced him to rely more on non-Whampoa generals, who commanded the provincial armies and many of whom had questionable loyalty to Chiang. Because of the reduction in his military power, Chiang lost some of his political leverage over local warlords. In effect, Chiang Kai-shek was effectively only the head of a loose coalition, rather than the commander-in-chief of a united fighting force. The sapping of China's best fighting men also made the planning and execution of subsequent military operations difficult. In essence, Chiang Kai-shek's concerted pre-war effort to build a truly effective, modernized, national army was greatly devastated by the sacrifices made in the Battle of Shanghai.