Lessons Learned From Yugoslavia
The Yugoslav wars marked a horrendous end to the 20th century - but to truly understand the Yugoslav wars, one has to look no further than the Middle East.
There is no difference between the political situation in modern-day Iraq, and the political situation in Yugoslavia. Yugoslavia was a state of multiple different groups of people brought together by authoritarian rule. Iraq, likewise, was only held together by the iron fist of Saddam Hussein before his ouster in 2003. Following the fall of Hussein, Shiites, Sunnis, and Kurds are now engaged in bitter fighting. In many aspects, Yugoslavia was actually better than Iraq - in Yugoslavia, there was some pan-Slavic ideology to construct the framework of a Yugoslav state, whereas Iraq is a country defined by arbitrarily drawn lines on a map.
One does not have to look very far, in the Middle East, to see more mini-Yugoslavias. Syria is 70% Sunni, but is ruled by Alawites. Yemen is roughly 60% Sunni and 40% Shia. In Africa, meanwhile, the borders have no resemblance to the ethno-linguistic groups in the continent. It is no coincidence that the larger states in Africa (Sudan, Congo, and Nigeria) have also seen the most violence - by their very nature, they comprise of more ethnic or religious groups and are thus more prone to conflict.
Source: Harvard Africamap Project
Furthermore, larger, pan-ethnic or pan-religious states can also exist. Take the United States, for example, which is comprised of a hodge-podge of ethnic groups. India, likewise, is arguably the most diverse country on the planet - yet is more stable than Iraq or Yemen. This is because both India and the US have their own identities - people identify as Indians or Americans instead of Assamese or Germans.
Borders must be drawn to emphasize a specific identity. The current Iraqi borders emphasize no identity - Iraq is a geometric, not political, construct. However, a pan-Arab state (stretching across the entire Arab world) could hypothetically succeed - an Arab identity does exist, and a nation could be built off of this identity. On the flipside, dividing Iraq into Sunni and Shiite states is also viable (and more plausible), as the identity is now based on an Islamic sect. Current borders in the post-colonial world do not reflect this - there are Arabs, Muslims, Christians, and North Africans, but there is no such thing as a "Malian" or "Central African Republicanese".
In an ideal world, some sort of conference would be held to redraw national borders in order to reflect this need. However, this ideal world does not exist. Arbitrary borders have granted some countries tremendous amounts of natural resources, which they would never give up. There would be huge disputes on where exactly the borders would lie, and some countries would need to be entirely gutted. With this in mind, there is a "next best solution" - foreign investment.
There is a strong correlation between violence and poverty. Artificial states can still thrive - take Saudi Arabia, for example - and they can survive because the citizens are rich enough so that fighting is no longer beneficial. In contrast, rebels in the Congo use ethnic divisions to justify war - during which, they mercilessly loot and plunder everything they come across, making huge profits in the process.
Foreign investment works because it reduces the focus on internal divisions within a country. In a poorer country, there will be a natural tendency to blame suffering on another ethnic group. The solution, therefore, is either to shift the borders (an impossible proposition, as discussed earlier), or to end the suffering through economic aid. There is no reason to wage war when you have a strong economic footing - you have everything to lose and hardly anything to gain. In contrast, if you have a weak economic footing, the risk/reward gamble favors war, as exploitation becomes possible.
Foreign investment isn't a one-way street either - it is a mutually beneficial process. China's OBOR initiative, for example, will greatly boost Chinese exports. Even if the economics aren't favorable, the politics are - China will find itself with a host of new allies across three continents. Foreign investment gains allies, builds alliances, and boosts stability.
If the United States truly wants to see a peaceful and stable world, the first step is to invest in foreign countries. I've already discussed this in the case of Africa, but this is also entirely possible in Latin America and the Middle East. Without economic stability, there can be no political stability - and terrorist groups and civil wars will continue to plague the world.