The fact is we live in a capitalist world. One of the crucial elements of this capitalist system is the flow of capital, commodities, and labour around the world. While it might seem for a second that the removal of borders would better facilitate all this, the opposite is actually true. From the perspective of the ruling classes of the world, particularly those of the strongest nations, breaking down borders would be a disadvantage for a number of reasons.
Multi-national corporations often rely on tariffs and protective trade policies to protect their market share and profits. For all their love of the “free-market,” corporations will run to the protection of their government when they feel threatened by foreign competition and these corporations have the greatest influence in politics.
Capitalists need a world in which they can freely move capital around, yet at the same time have access to cheap labour as well. Immigration is a major source of cheap labor, and borders and immigration laws are a major part of keeping wages low. If there were no borders and immigration laws, these labourers could demand better conditions without fear of deportation. The leading capitalist nations, either for the purpose of exploiting immigrant labor or just cheap labour within those countries, rely on maintaining an imbalance in the world backed up by borders and their immigration laws.
Borders and sovereign governments also play an important role in providing cheap labour because these states embroil themselves in a race to the bottom, in order to attract multi-nationals by offering tax-holidays and free-trade zones, in addition to the cheapest, non-union labor. If all these territories are no longer sovereign nations, this competition would be greatly hindered if not eliminated entirely. Corporations benefit from having various governments out-bidding one another for the cheapest labor and facilities.
Let us also not forget that the ruling classes of many nations are indeed in competition with each other. Is the American ruling class willing to share profits, power, and influence with those of the other industrial nations? Are the rulers of the EU willing to do the same? Capitalist countries will cooperate so long as it is profitable and beneficial, but sooner or later every market gets snatched up and a war erupts to re-draw the lines on the globe.
No borders would spell the doom of many corporations, which would no longer be able to depend on their government and their trade policies to protect their interest. They could no longer rely on their government to use its military or economic leverage to open one market while denying it to others, or to domestic producers in that country. Why would they give up such power?
Once we come to understand that the idea of a unified one world under the current system of capitalism is simply just not feasible, we must then consider the practical possibility that it can be created by socialism.