When sovereign governments execute their populations

It is well known the extent of global discussion about the excessive persecution by the Libyan government of its protesting population, prompting some to rightly call it a crime against humanity. But the world has largely just stood by, patiently waiting for the event to finish unfolding and reach a conclusion, whatever that might be; we're well aware that it might mean further killing of protesters and innocent citizens by the thousands until there is no more voice. The question then us bystanders have to ask ourselves is whether to intervene or not. Of course, out of basic empathetic response we, the plebeians of any country, wish to reach out and help the oppressed - if we could, yet our governments seem more reluctant to do more than condemn or impose sanctions. Each nation has a very complex political situation both internally and externally that would reasonably offer many reasons to mind its own business, but I think that there is a fundamental reason that overwhelms both the political class from taking concrete and direct action to help the Libyans, and ourselves from putting significant pressure on it to do so.
Sovereignty, and its sister Nationalism, have historically been concepts that got more and more defined during and after the 18th century. It is generally believed that an ethnic group has the right for autonomy and sovereignty, however, the world filled with examples of the contrary, Catalonia and Kashmir being cases in point. The fundamental premise of democracy is the representation of the will of the governed. Without dwelling on issues of majority vs minority, we can immediately intuit the need for boundaries that establish the spatial extent not only of the property of the governed (the Country) but also the limit beyond which their will should no longer has any real validity (neighboring countries could in theory have dramatically different laws). What happens then when the population of one nation wants to lend a hand to the population of another nation that is being pressed by their government?
In essence, once we get over the superficially of racism and the arbitrariness of cultural differences, we start identifying with each-other at level of the species; we are all humans and largely alike. Take this idea to an extreme and soon we realize that ethnicity, as a concept, starts losing grounds, and consequentially so does boundary. Existing power relationships are nullified and replaced by something more universal. It is not in the interest of those in power to share their authority, or those better off to share their property, due to a perceived downgrading of position in the socio-economic hierarchy, so group identity needs be invoked and reinforced top-down to keep the status quo, and boundaries between jurisdiction need be drawn and kept at all costs.
Governments condemn each-other for oppressing their people, but direct intervention would nullify the basic premises and validity of the power structure between the governing and the governed, and consequentially sovereignty. International affairs are full of "mind your own business". If it wasn't then there would be something that might be termed "international democracy" that basically merges all the existing power hierarchies into one global state - imagine a behemoth European Union. What king or leader would want that? Therefore difference needs to be artificially and actively sustained in order to provide validity to the boundaries of jurisdictions. In many cases from this is from the top down. "Minding our own internal affairs" means "we are not them" but also "they are not us" and thus the power structure's hierarchy remains in place.