A first objective of the research programme on Virtual Water Trade is to assess virtual water flows between nations and to draw the virtual water trade balances of all nations of the world by analysing both imports and exports. In first instance we consider virtual water trade in relation to international trade of crops and livestock products (such as meat, leather, milk, butter and eggs). In second instance some other products might be considered, such as paper and cotton. A second objective of the programme is to analyse the virtual water trade balances of nations within the context of required and available domestic water resources, to evaluate the trade balances in terms of economic efficiency, water and food security, and sustainability, and to develop alternatives for improved global water use efficiency. For a glossary of terminology on Virtual Water and Water Footprint, please visit http://unesco-ihe.org/downloads/projects/glossary.doc.