During the late 1970s and 1980s, the IMF, World Bank, and key donors worked closely to promote reforms to counter the effect of inefficient economic policies and practices. By 1984, a combination of factors, including drought, inflation, and confused application of Islamic law, reduced donor disbursements and capital flight led to a serious foreign-exchange crisis and increased shortages of imported inputs and commodities. More significantly, the 1989 revolution caused many donors in Europe, the U.S., and Canada to suspend official development assistance, but not humanitarian aid.