<P>During the last decades, it has become increasingly clear that demographic change constitutes one of the most important challenges of the 21st century. One important factor that has placed demographic change high on the political agenda is an increasing awareness of current demographic trends. It is well known today that we can expect a dramatic increase in the number of elderly people in Europe, due to declining mortality combined with continuing low fertility. The working age population in Europe will decrease. This process of ageing in Europe is the closing phase of the demographic transition, a shift from high to low birth and death rates that started in the 19<SUP>th</SUP> century. </P><P>The main question this book focuses on is to what extent European external policies should be reconsidered in the light of current demographic challenges. Experts from Europe and the US concentate their study on current demographic trends, an analysis of demographic transitions and their economic, social and geo-political implications and European migration policies.</P>