Poor and unemployed youth are widely considered a threat to political stability, often blamed for everything from fights to crime, riots and revolutions. Ex-combatants cause special worry. Not only do they have professional experience in warfare, and hence some comparative advantage in violence, but their social networks may also be dense with potential recruiters. War may also have left them poorer or more traumatized than their peers. Each of these factors could elevate the risk of rebellion, crime, or other aggression, risks greatest in weak states and uncertain economic climates like that of Liberia.