Preparation for nation-building requires that responsible political leaders consult both with regional and functional experts, those who know why the society in question descended into conflict and those who know from experience elsewhere how to put such societies back together. Goals must be established which transcend the most immediate and normally negative purposes of the inter vention, e.g. halting conflict, stopping genocide or turning back aggression. These positive goals must be commensurate with the scale of military manpower and economic assistance likely to be committed. The larger the social transformation envisaged, the greater the resistance likely to be encountered. The most common cause for the failure of nation-building endeavours is a mismatch between objectives and commitments.