Why is militarism considered a long term cause of ww1

Since the late 19th century, the European powers made political and military alliances among themselves, often through secret negotiations and with secret clauses. A negative consequence of these agreements was that they gave little space for flexibility and diplomacy in case of a major confrontation between two rival powers. There was a high probability that if war erupted between two great powers, this web of alliances would drag other great powers to war because of their compromises. This happened actually in 1914 and it's seen as a major cause of WWI.