Centralization and decentralization are not "either-or" conditions. In most countries an appropriate balance of centralization and decentralization is essential to the effective and efficient functioning of government. Not all functions can or should be financed and managed in a decentralized fashion. Even when national governments decentralize responsibilities, they often retain important policy and supervisory roles. They must create or maintain the "enabling conditions" that allow local units of administration or non-government organizations to take on more responsibilities. Central ministries often have crucial roles in promoting and sustaining decentralization by developing appropriate and effective national policies and regulations for decentralization and strengthening local institutional capacity to assume responsibility for new functions. The success of decentralization frequently depends heavily on training for both national and local officials in decentralized administration. Technical assistance is often required for local governments, private enterprises and local non-governmental groups in the planning, financing, and management of decentralized functions.