Senegal is a trading hub and has one of the largest economies in the West African Economic and Monetary Union (WAEMU) sub-region. The tax and legal systems are well-developed and amenable to foreign investors and the government has worked to cultivate diverse links with investors in the US and Europe. The main security risk is the re-emergence of the separatist rebellion in the southern Casamance region and ongoing instability in neighbouring Guinea Bissau. Other operational barriers include susceptibility to corruption and the propensity for labour unrest, although these are considered relatively minor.