If companies can merge for mutual benefit. Then why cannot entire countries?
Take for example Japan. Its area is approximately 145,925 mi² with a population of 127.3 million (2013).
Its a developed country, high level of education and wealth and overall social development.
Its per capita income is $38,633.71 USD (2013).
Lets now look at The Democratic Republic of the Congo.
Its area is 905,600 mi². A huge increase over Japan.
Its population is 67.51 million (2013). A huge decrease as compared to Japan.
It has huge deposits of gold, copper, cobalt, uranium, diamonds and oil. Its per capital income is about $484.21 US (2013).
Japan has the money and the technology and is running out of space along with a scarcity of mineral resources. Frequent earthquakes is another huge problem for Japan.
While not advocating colonialism of the likes of Belgian Congo, a voluntary merger between Japan and The DRC could solve many problems that the people of DRC have not been able to solve for themselves. And too many lives have been lost due to vested interests in The DRC who probably will not all the country to ever reach its fully potential in a few more decades. I believe that the people of the DRC who are sick of the status quo could vote for such an arrangement. The U.N. could also buy into this idea and especially since Japan has been a pacifist nation since World War II.
Japan will need to invest substantially in security forces but with a promise of equitable access to the wealth derived from mineral resources for all DRC citizens, I think such an arrangement can have immeasurable benefits for both countries.
This blog post is too simplistic an explanation for such an idea. But you do get the general idea.