Through out history there has been a number of migrations, at times forced, and invasions that result in either new nations being created or loss of territory. Many times it’s not just a transfer of control of territory but an influx of a new culture displacing the prevous one. We find this situation with Alexander the Great. The Macedonians had adopted Greek culture and language. Eventually they were the point of the Greek spear into Asia Minor. Alexander comes to the throne after his father’s death and puts in place his father’s plan to defeat the Persians. To make a long story short, history tells us that as Alexander was defeating the Egyptians, the Phoenicians, and eventually all of Persia he dragged the Hellenistic culture with him. By doing this he changed the culture in that part of the world for a millennia and made Greek the international language for centuries.
Other times the invaders adopted the culture of the vanquished. Again we can turn to Greek history to the times of the Minoans. There is some scholarly difference of opinion as to the actual mechanism of the Minoans falling to the Mycenaean but after a few centuries the Minoans fell. The interesting aspect is that the Mycenaean adopted the Minoans, but when they came to power the Mycenaean operated the society as the Minoans did.
There are those instances where migration and a mixing of cultures over borders happens during the course of decades or possibly over a century or two. There are a number of examples of this scenario. Probably the one that is most likely known from high school but usually misunderstood is the Barbarian invasions into the Roman Empire. The over all impression left from a high school class is the barbarians, sometimes actually referred to as Germanic tribes, invaded the empire and sacked Rome. In some enriched classes in accredited high schools they may entertain concepts such as the Huns invasion into Europe and the use of German tribes as mercenary troops.
Scholars in the past generally agreed that various Germanic tribes caroused around Europe fighting each other or entangling themselves in battles with the Celts living in the area. Germans and Romans eventually clash in CE 9 with the decimation of the Roman troops. From that time onward the Romans made few large scale probes into German territory. Over time some Germans migrated in to Roman territory as farmers and even slaves and eventually a sort of parity developed between the two. The Huns changed this situation when they invaded Europe. They swallowed up eastern Germanic tribes outside the empire and drove others into the arms of the Romans. The Romans who were finding defense difficult against the Huns drafted individual Germans and in some cases whole tribes into the military. The Visigoths were one such tribe that was drafted into the Roman military. As the Huns dwindled after Attila’s death the Germans continued to infiltrate and defeat Roman legions with the Visigoths eventually sacking Rome.
Modern scholarship points to a little different situation. True the groups of people labeled Germans were tribal and yes they did defeat Roman Legions in CE 9, but there was ea balance between the Romans and the Germans. Dr. Norman Etherington in his American Historical Review points to recent scholarship that the Germans were not some “fur-clad invaders from far away” but they were groups and in some cases villages outside the borders of the empire. Over time Germans migrated into the empire peacefully. The Visigoths came into the empire as Roman troops and because of mistreatment went to war and sacked Rome in CE 410.
By the time the Huns (CE 451) came into the picture, the ‘German’ populations were not just along the borders but were numerous in parts of the interior. The Huns put pressure on groups outside of the empire and drove those already inside deeper into Roman territory. The Romans and Germans held a line against the Huns but the pushed migration of Germans into the empire changed the demographics in such a way that eventually the empire in the west collapsed. There were internal battles and starting in CE 527 some re-conquering of territory by the Byzantines under Justinian. With the short lived victories Western Europe fell into various tribal governments. The aspect of this event to take note of is that the Germans didn’t so much invade, as heavily migrate into better territory and over time became the majority culture.
In our modern world we find similar problems. The situation with Kosovo and the Serbians has the same overtones. Kosovo since antiquity was seen as a part of the Serbian homeland. Kosovo today is an enclave of ethnic Albanians and a minority of ethnic Serbians that is a recognized international state. Its beginnings however are tied much closer to Serbia. In fact Kosovo is remembered by many as Old Serbia and since the 1100s as the homeland of the Serbian people. In the 1400s the Ottoman Turks controlled the region and with the end of World War One the region was coalesced into what would in modern history be called Yugoslavia. With the Tito and the communist era Kosovo was seen as a semi-autonomous region of Yugoslavia. With the 1990s, Serbian irredentist feelings gave rise to its claims over Kosovo. Its arguments included the history of the area and the ties to it as their homeland. The new residents were appeased and on June 16, 2008 with the backing of the United States, Kosovo was recognized with full international status.
We now look at the US southwest. One has to wonder if the US will support a similar situation there as it did with Kosovo. We have seen from the history of the past two centuries how the US treated its indigenous populations and how Indian land was reallocated. In fact most of the west including California, Arizona, New Mexico, and Texas was all part of Mexico. The population was a mix of Indians, Spanish Europeans, mestizos (Spanish-Indian), and Criollos (European descent born in America). However, through the conquest of the US government and their imperial notion of Manifest Destiny these groups of people were either expelled or subjugated by the new government administering the area. This situation has persisted with border travesties occurring and within the last 30 years increasing. The demographic differences in the southwest are now detectable because of migration. Peoples who were divorced from their ancestral homes are migrating back and not paying attention to borders. They’re not invading, but moving to an area that is economically better. As of 2008 13 million illegal immigrants were living in the US. The immigration pattern isn’t that different from what was going on with the Germans into Roman territory, or Albanians into Kosovo. The situation of immigrants moving to an area that has superior economic advantages will eventually change the demographics with the foreign (new) culture becoming the majority culture.
Looking at this situation it seems if things continue the southwest of the US will eventually become culturally Mexican and predominantly Spanish speaking. Judging from history it would not be impossible if the southwest was reunited to Mexico or as with Kosovo, made independent. There are a number of reasons for this. The territory was originally Mexican so there are national and political irredentist aspects involved. Additionally, the Mexican population in the US southwest is climbing and in some areas becoming the majority. What would the US response be if a majority of the UN Security-Council called for a demilitarization of the Southwest border of the US or as in the case of Kosovo, just determine it to be a separate entity? Would the US government be as supportive of the geopolitical change in the US southwest as they were with Kosovo, or for that matter as with Croatia and Slovenia? Would the US government still think what is good for the goose is good for the gander? If it occurs will it be seen as a migration or an invasion? Probably what is written will depend on who writes it, the immigrant or the government.
 Etherington, Norman. 2011. Barbarians Ancient and Modern. The American Historical Association 116 (1):31-57.
 Jansen, G. Richard. Albanians and Serbs in Kosovo: An Abbreviated History, an Opening for the Islamic Jihad in Europe, Colorado State University, July 22, 2008 April 25, 1999 (accessed Dec 20, 2009) http://lamar.colostate.edu/~grjan/kosovohistory.html.