The relationship between the two nations, however, has been described as "roller coaster" given by the characterization of close coordination and lows marked by deep bilateral estrangement. From 1979 to 1989, the United States and Pakistan cooperated in funding and financing of Afghan mujahideen who engaged the Soviet Union, the relations took a deep dive with the introduction of unilateral military embargo over the covert development of nuclear weapons which Pakistani administrations saw their program as only way to defend the nation in light of India's larger military conventional attack in 1990. With sanctions waived off in 1994 with Pakistan's willingness to participate with the United States in wars in Somalia and Bosnia, the United States again suspended the aid and imposed sanctions along with India in 1998, only to be lifted again with United States engagement in Afghanistan in 2001.