I can't find the original source, but someone once said that a language is just a dialect with its own army. People my age have had to get used to this, what with the proliferation of new countries since 1990. Europe now has fifty sovereign states, which is why the Euro 2012 football championship takes two years to get from the qualifying rounds to the final. If they'd held it in 1875 (and if England, Ireland, Scotland and Wales didn't insist on competing separately), they would only have needed a three-way play-off between Montenegro, Andorra and Luxembourg before getting straight down to the last 16.
Language gets intimately tied up with politics. A dialect often becomes a language simply because the map-makers have started drawing new borders. A Slovakian friend recently lamented that his younger countrymen could no longer understand Czech, whereas he could because he was born in Czechoslovakia when it was still one country with one language. My friend from Kiev claims she can speak Russian pretty fluently, whereas I'd always thought Ukrainian was just a dialect of Russian, partly because it was (almost) never a separate state. Another friend whose native tongue is Flemish has no problems holding a conversation in Dutch (and, being fluent in Swedish, claims to find Danish reasonably easy), while her French needs a little work, meaning she understands the people of the neighbouring country better than half of her own compatriots.
When I visited Yugoslavia in 1974, I was told "the language" of the country was Serbo-Croat. That single language is now four: Serbian, Croatian, Bosnian and Montenegrin. If the distinction seems political, you could easily argue that the idea of a single Serbo-Croat language was just as political.
Similarly, Norway has spent most of its century of independence promoting Nynorsk ("New Norwegian"), an artificial recreation based on older Norse dialects, as a way of distinguishing Norwegian from Danish - the language of its foreign occupier till 1814.
This is all very confusing to those of us brought up in an era when it was thought that 1 country = 1 people = 1 language, with the exceptions of a few awkward minorities like the Welsh and the Basques and the outer provinces of the last two empires: the USSR and China. The lesson is clear: you aren't a nation without your own language.
And yet the UK and the USA have been separate countries for a couple of centuries now, but they still maintain that they speak the same language: English. Still, America has been assiduously developing a different style for about 170 years, which enables the Americans and the British to argue about what is 'right'. This provides fuel for plenty of transatlantic bickering of every hue, from the illuminating to the infuriating and the downright silly. The arguments are also spiced up by Australians, South Africans, Canadians, Scots and others who feel that their own variations of English are just as valid and who hate being ignored.
Disparage his language, and you'll find that even the most liberal of internationalists sleeps in pyjamas cut from the national flag.