The nations of Western Europe face a significant problem in the twenty-first century because declining birth rates and higher life expectancy have led to an aging population. This will mean that there will soon be a great many more people claiming retirement benefits and not contributing directly to the productive capabilities of the nation than at any other time in European history. Essentially, there may be too few people in the workforce to support the needs of the population.

The environmental movement emerged in Europe in the 1970s and was quickly politicized in many countries. In most European countries, the environmental parties, often called “Green Parties,” have had little electoral impact. But, in first Belgium and then Germany, they quickly emerged as a significant political force and have participated in numerous coalition governments.

The Polish Solidarity movement was founded in 1980 and was the first trade union to operate independently of the Soviet Union and the Warsaw Pact. It was wildly popular in Poland in the 1980s and formed the first Polish government after independence from the Soviet Union.

All of these countries are members of the European Union except for Norway. Norway, although not a participant of the European Union, is a member of the European Economic Area (EEA), which allows Norway to be part of Europe’s single market.

When the Maastricht Treaty was signed in 1991, formally codifying the European Union, it is estimated that illegal immigration into the countries that make up the European Union was less than one-hundred thousand individuals per year. In recent years, by some estimates, more than a million people arrive illegally into the European Union each year. Although the exact numbers are not agreed upon, what is certain is that the number of illegal immigrants arriving in Europe each year has increased dramatically in the last two decades. This presents a significant challenge to the member countries of the European Union in the years to come.

The Socialist Federal Republic of Yugoslavia was created in 1945, and contained Slavic, Balkan nations that had ethnic, religious, and cultural differences. In the late 1980s, these long-simmering problems boiled over, and the constituent nations sought greater autonomy from the Communist government and eventually to declare independence. From there, nationalist parties took over the local governments, with ethnically similar armies fighting wars that often bordered on genocide as the various nations established new boundaries and governments. Fighting continued until 2001, when the Republika Srpska army was fully disbanded.

Otto von Bismarck is credited with unifying the various Germanic states into one nation. He was appointed Minister of Prussia by Wilhelm I of Prussia in 1862, and he used that position to wield a great deal of power. One of his most famous tactics was engaging in wars with Austria, France, and Denmark in order to unify the various Germanic states behind a single cause and also to gain some territory. In 1871, von Bismarck's work culminated in the formation of the German Empire with Wilhelm the first as the Emperor and himself as chancellor. He held this post until 1890, when Wilhelm II became displeased with him. He initiated many reforms meant to create a strong unified state and is revered by German nationalists.

Initiated in 1848, the Peace of Westphalia was made up of treaties that ended the Thirty Years’ War and the Eighty Years’ War. The Peace of Westphalia helped to create the idea of state sovereignty, where individual states could determine their own laws and other states had to respect the right to do this. While this was not always upheld, it was the first time this had really been established in an international setting. Some of the major points involved giving independence to Switzerland, allowing a sovereign ruler to determine the official religion for the state, protecting Christians if the official religion of their state was a different sect of Christianity than the one they practiced, and overall, recognizing the authority leaders have within their own state.

In the years leading up to and following the Second World War the United States took the lead in scientific and technological investment and advancement. This had direct consequences for the countries of Europe as many of the best and brightest scientists of the twentieth century emigrated to the United States, taking their work with them. This is called the “brain drain.”

All of these countries are members of the European Union except Turkey. Turkey has been making overtures to the European Union for several years in the hopes of gaining admittance, but as of 2015 remains excluded from the European Union and the Common Market.