In November 1947, a brief democratic period was ended by a military coup and the Thai economy regained its momentum. In his dissertation, Somsak Nilnopkoon considers the period from 1947 to 1951 one of prosperity. By April 1948 junta Phibulsongkram, the wartime prime minister, returned to his previous office. He, however, was caught in a power struggle between his subordinates. To preserve his power, Phibulsongkram began an anti-communist campaign to seek support from the United States. As a result, from 1950 onward Thailand received military and economic aid from the US. The Phibulsongkram government established many state enterprises, which were seen as economic nationalism. The state (and its bureaucrats) dominated capital allocation in the kingdom. Ammar Siamwalla, one of Thailand's most prominent economists, calls it the period of "bureaucratic capitalism".