1. why did european politics become so crisis-laden in the first decade of the 20th century?

Due to imperialism and nationalism the tension within the countries got greater and greater.  Nations were competing with each other for power and started reinforcing their armies which was quite expensive. People started getting rather unhappy and poor.

Each nation had their own problems further more

1. Russia was tired of waging endless wars, the people were starving and the idea of communism seemed very promising

2.The Austro-Hungarian empire was very large and included provinces that spoke other languages and felt the need to be part of an other country

3.Italy was a new nation which had to catch up with other countries...(it managed to build a quite impressive navy though)

4.France had Napoleon in the last century...that was a rather unpleasant turn of events, especially for those who had believed in theideals of the French revolution