Problem is that there are other countries that would use the vacuum left behind to further their ambitions. In a way colonization is still relevant in all developing countries.
An informed and empowered populace is a check against imperialism/colonization. Look at the opposition to the Vietnam war, for example. With the existence of the global internet, it has become much easier for citizens to track what their governments are doing. I think that we can decrease inter-country domination over time by pushing for more democracy and education worldwide.