Military internationalism formed the crux of Cuba's foreign and military policy for almost three decades, and was subordinate only to domestic defense needs. Its support for resistance movements in Central America contributed to Cuba's diplomatic isolation in that region and was instrumental in triggering its suspension from the Organization of American States. Internationalist operations ranged from varying degrees of covert activity and espionage to the open commitment of combat troops on a large scale. The Cuban military presence in Africa was especially notable, with up to 50,000 troops being deployed to Angola alone.