Norsemaiden - the blood of the North is strong, and we will always survive. However, I'm not convinced that Western Civilization will crumble - it will almost certainly change, just as it has many times over the millenia. I think Islam is destined for failure, not expansion; we may have a war with China, but an invasion of Europe or the US is not likely because of many factors, not the least being the geographic difficulties and the nuclear arsenals of both sides.
But to get back to the main topic - Norsemaiden, you are absolutely correct that the historical perception of the Norsemen exaggerates the supposed military savagery of the Vikings without putting it in any context. The fact is, the most lasting impression that the Vikings made on the world was not due to the raids and battles, but the exploration and settlement (Iceland is the best example, as well as Normandy, Ireland, England, parts of Russia, etc.), and the far-ranging and entrepeneurial trading throughout the world, which is clearly a progenitor of our own economic system today.