Its hard to say about these things one event like this caused it, It was a chain of events, like dominos falling. There was the famine, the monarchs lavish spendings, the greed of peoppe lusting for there power, misunderstandings and ignorance on all sides, I think the tennis court oath was mearly one of the first manifistations of a chain of events that had been going on for a long time, the real war started when the events was trigged and not stopped, and when it went into actions it declined into an anarchy of death that would last for decades. The storming of the bastile was a important role in the events, when the women stormed the palace and the queen had to hide, if they found her they would of torn her to shreds.