There is one more area which must be considered and that is neocolonialism. What this is depends on who is defining it. Socialist or communist writers have defined it as the efforts of the former colonial powers to maintain colonial control by other means. This definition lacks precision, as some of the neocolonial powers were in fact previously colonies, such as the United States. A largely accepted definition of neocolonialism is as follows: it includes retention of military bases, exploitation of resources, preferential trade treaties, imposed unification of colonies, conditional aid, and defense treaties. It also includes artificially created countries or combining countries into a group or federation. However, this grouping of countries is ill-defined in terms of whether they represent neocolonialism or not, as some of the Third World countries created in such combinations contend they are not dependencies in any way, although they may retain economic ties with the metropolitan power that previously held sway there.