Many aspects of the inter-annual variability of the Indian summer monsoon (ISM) remain unexplained. While boundary forcing like SST, snow cover and land surface processes are known to play significant roles, they cannot explain all of the inter-annual variability of ISM. We identify and show that nature and organization of dynamics play a critical role in the intensity, and hence the variability of ISM. Investigation using a 55-year dataset from NCEP at different scales and locations clearly shows a sharp contrast in organized convergence at a scale of 20¿ between excess and deficit monsoon years; the deficit monsoon years, including 2002, are marked by suppressed organized convergence. The general conclusions are valid even in presence of moist convergence, indicating that it is the efficient organization through convergence that plays a critical role in monsoon intensity. The results thus provide new insight into the dynamics and simulation of monsoon.