Over the next twenty years, the BZNS remained a part of Bulgarian politics, but it began to falter for lack of a concrete ideological base. Aleksandar Stamboliyski saved the party from that plight by first publishing a series of theoretical articles on the peasants’ role in the state and history, and finally taking control of the BZNS party. In 1909 he wrote the book "Political Parties or Estatist Organizations", which laid the foundations for the ideology of the BZNS. Stamboliyski rose through the ranks of the BZNS and by 1918 had become the leader of the party. World War I left Bulgaria in a state of severe social and economic crisis, and after a series of worker and peasant strikes and uprisings between 1918 and 1920, the Bulgarian army and all old political parties were essentially discredited. In 1920, by a combination of major popular support and some coercive methods, Stamboliyski was able to create a BZNS controlled government. The party also formed a militia, the Orange Guard.