The Arch-Heresy of Our Time

Nonsense, the trends over the past centuries are much more complicated; political units of all sizes and types (depending on how you define them) have been constantly merging, expanding, crumbling and decentralizing in various forms and degrees. It all has to do with the perpetual evolution of administrative, social and economic efficiency of exercising power in a given polity.

Take Europe in 1648 after Westphalia when the concept of a sovereign polity was finally hammered in international accords. There were almost 2000 sovereign states in that continent alone (most of them under the de jure authority of the Holy Roman Emperor, but de facto mostly sovereign and independent running their own affairs); with hundreds and hundreds of currencies in circulation.

Then take Europe 1914, where the count of sovereign states had been reduced to 25. This count has approximately doubled today; it is however much less than what had existed in the not too distant past.

What one might document over this time period, though, is the increasing acceptability of the equation nation = state. When there were thousands of little de facto independent states, they were "the property of princes", peoples and ethnies actually having little if any role to play. When we get to pre-WWI Europe, even though there were multinational states (the Habsburg monarchy being the obvious example), the various nations in them had already developed (to varying degrees) national demands and feelings of injustice about being dominated by other ethnic groups (e.g. Greeks in the Ottoman Empire, Serbs in Austria-Hungary); and those states (like France) that aggressively defined themselves as based on a common ethnic history were culturally very influential.

The reduction of the number of states in pre-WWI did not work against this tendency; rather, the percentage of states that were ethnically based (like France, which defined itself quite aggressively in terms of a common ethnic history) increased, and if the absolute number of states decreased it was mostly as a result of the success of some of those states in conquering and submitting others. Inasmuch as the conquered peoples could be absorbed and integreated, the situatino remained (e.g. the Sorbians in Germany); inasmuch as they couldn't, the final result was nationalistic demands for independence (e.g. the Serbians, and most other 'downtrodden nations' in the Habsburg monarchy; the Greeks in the Ottoman Empire; etc.).

Today, the nation = state equation becomes stronger and stronger: the Baltic states see themselves as ethnically based (hence the idea of the Russian minorities as 'a problem created by Stalin' rather than as part of their -- multi-national -- citizen basis), Russia, despite official claims to the contrary, acts more and more as if it thought so too ('Russia for the Russians'); even when the reality is that big powers are using them as pawns, small countries still want to declare independence based on an ethnic basis and a history of ethnic conflict (Kosovo, Abkhazia, South Ossetia).

This looks more like a reliable modern tendency.

From a perspective of certain countries in the West like France, Germany, Poland, Greece, Turkey and Italy, etc..., you might have a point. However I hardly view this as a dominating global tendency, thus proving my point that development of political units are much more complex and not solely due to a nation or ethnicity, however you may define one, mobilizing a state around itself.

Two concrete examples:

Pretty much the whole Arab world still exists and appears to be continuing to exist in the form of sovereign medieval "properties of the prince", as you describe 17th century Europe. Despite the post-colonial surge of pan-Arabism and the phenomenon of ‏الوطن العربي‎ (or "The Arab Nation"), the Arab world still remains extremely fractured and divided due solely to the legacy of externally imposed political systems and rectangular colonial borders. Sure, the Arab language has evolved into dozens of regional, but still mutually intelligible, dialects, but so has German despite the existence of a German "nation-state". For more analogous and extreme cases, take a trip to sub-saharan Africa.

Now take another curious example: India, a Federal Republic holding more than 15% of the world's population, comprised of thousands of ethnic groups and languages (most of them not recognized in official governance) and holding virtually every major religion on earth (including the third largest Muslim population in the world, after Indonesia and Bangladesh respectively). And it is a democracy! You tell me how this country has been able to form under your Eurocentric paradigm.