In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
Q: What did Russia believe to be a large source of failure?, Context: The Crimean War marked the ascendancy of France to the position of pre-eminent power on the Continent,:411 the continued decline of the Ottoman Empire, and the beginning of a decline for Tsarist Russia. As Fuller notes, "Russia had been beaten on the Crimean peninsula, and the military feared that it would inevitably be beaten again unless steps were taken to surmount its military weakness." The Crimean War marks the demise of the Concert of Europe, the balance of power that had dominated Europe since the Congress of Vienna in 1815, and which had included France, Russia, Austria and the United Kingdom.
A:
military weakness