:So their will be a lag time, probably a generation or two - during which the west must be stagnant.
What would that estimate be based upon? I thought more two generations (40ish yrs) because of the sheer scale of work required and the need to hold back western growth meanwhile.
No, the west need not be held stagnant, indeed it will have to grow itself (though in new directions- more housing, clothing and basic necessities, less weaponry etc.).
The point is, contrary to popular theory, The population of the USA is not expropriating the wealth of otehr nations- Imperialism takes the form, rather, of securing cheapaccess to natural resources (primary industries), and enforcing open markets (to sell your own goods). Since the post-colonial world still has an economic base geared almosts solely around primary resource production, this means that they are held within it, and cannot slap on tarifs in order to develop their own industries and economic bases. i.e. the Market/imperial/political system is holding back their development, not imperialists countries as a whole (though Western capitalists do expropriate capital from smaller countries, like united Fruit in South America).
Western nations do not have to be 'held back' to help the third World develop- it can develop itself, using the freely available aid and tech from the devloped world- because its one world economy, growth in the (ex)US would mean more to be had in Gambia or Uganda- and that does not mean 'levelling down' or redistributing, but equal access to knowledge, skills and tech, and food, etc.