KrazyKat said:
I think that countries and nations are far closer to being just man-made terms to define areas than something like Europe, especially many of the countries created through colonialism. If Europe is jsut a term to define an area it isn't a very good one since its very hard to come to a definate conclusion of where exactly does it end? Does it include Israel which is in the eurovision song contest, or North African countries that want to join the EU - and were part of the Roman Empire? Perhaps it could even be seen as the extent of Christianity? It can also mean jsut the EU, or just continental Europe.
Europe clearly does not include North Africa or Israel. But Russia is definitely part of the European civilisation (more than Turkey, which is "half-European" from her mother-side

).
I clearly see there being a European culture and common history. However, each country or region within Europe doesn't share all of this common culture and contains parts that are unique to itself.
No need to state the obvious. If China were to plit up in 20 countries, you could also say that each of the country had its own culture (different food, different languages), and some shared more together than others. Same for India. It may be difficult if you haven't studied about world cultures, but there are undeniable similarities shared between countries within Europe, South Asia and East Asia (not so much South-East Asia though) so that we can define them as "civilisation".
A civilisation goes beyond political borders. When I speak of "Indian Civilisation", it includes Pakistan, Bangladesh, Sri Lanka, and to a lesser extent also Nepal and parts of Afghanistan. When I speak of "Chinese Civilisation", it includes Taiwan, Japan, Korea and Vietnam (but maybe not Tibet), not just the People's Republic of China. Modern countries are only made to confuse us as the generally do not fit with cultural borders. It's confusing to talk of "Indian" civilisation when a country is also called India but the borders of both do not match. Just remember that historically the region was divided in dozens of countries, with empires rising and falling, some just in the North, others in the Sout, and others indluding most of the Indian subcontinent. It's the same as in Europe.
China too has been divided in various kingdoms, and some empires included Vietnam, Korea, Manchuria or Tibet, while others didn't. None included Japan, but trade, political and cultural ties with Japan were always strong. Ethnically, the Japanese are much closer to the Chinese than the Portuguese are to the Finns. Linguisticially too (Japanese got 50% of its vocabulary from Chinese, a similar proportion as to what English got from Latin).
South-East Asia could hardly be called a civilisation because many of these countries do not share much in common. Ethnically, some people are white-skinned (e.g. Vietnamese, Thai...), other dark-skinned (e.g. Cambodian, Indonesian...). Some languages are related to Chinese (e.g. Vietnamese, Thai...), others are not (Indonesian, Tagalog...). Some countries are Buddhist, others Muslim, others Christian. Cultures evolved differently enough not to be part of a bigger whole. That's probably caused by the high fragmentation of the region in islands and peninsulas. Malaysia, Indonesia and the Philippines could maybe be regarded as the same civilisation though.