WASHINGTON — Even as the United States poured billions of dollars into foreign military programs and anti-terrorism campaigns, a small core of American government-financed organizations were promoting democracy in authoritarian Arab states.

The money spent on these programs was minute compared with efforts led by the Pentagon. But as American officials and others look back at the uprisings of the Arab Spring, they are seeing that the United States’ democracy-building campaigns played a bigger role in fomenting protests than was previously known, with key leaders of the movements having been trained by the Americans in campaigning, organizing through new media tools and monitoring elections.

A number of the groups and individuals directly involved in the revolts and reforms sweeping the region, including the April 6 Youth Movement in Egypt, the Bahrain Center for Human Rights and grass-roots activists like Entsar Qadhi, a youth leader in Yemen, received training and financing from groups like the International Republican Institute, the National Democratic Institute and Freedom House, a nonprofit human rights organization based in Washington, according to interviews in recent weeks and American diplomatic cables obtained by WikiLeaks.

The work of these groups often provoked tensions between the United States and many Middle Eastern leaders, who frequently complained that their leadership was being undermined, according to the cables.