Most interventions by outside forces to promote democracy in post-conflict states since WWII have failed. The most successful were in societies, such as Germany and Japan, featuring relatively high per capita GNP and diversified middle class economies. Among societies in general, prospects for democracy tend to diminish as per capita GNP decreases. The effects of conflict make democracy promotion considerably more difficult, particularly when poorer societies are plagued by weak institutions, corruption, religious extremism and ethnic, religious or factional animosities. Even if outsiders are able to control violence and actively promote democracy, success will depend on the underlying political culture and willingness of key political actors to play by democratic rules once the outsiders have gone. Hence, outsiders need to develop the best possible understanding of their prospects for success before committing to intervention, particularly when the resource demands are likely to be high.