Activists of the Orange Revolution were funded and trained in tactics of political organisation and nonviolent resistance by Western pollsters and professional consultants who were partly funded by Western government and non-government agencies but received most of their funding from domestic sources. According to ''The Guardian'', the foreign donors included the U.S. State Department and USAID along with the National Democratic Institute for International Affairs, the International Republican Institute, the NGO Freedom House and George Soros's Open Society Institute. The National Endowment for Democracy has supported democracy-building efforts in Ukraine since 1988. Writings on nonviolent struggle by Gene Sharp contributed in forming the strategic basis of the student campaigns.