Complex sentence: The brigade was reformed in 1939 in response to the outbreak of the Second World War, up until 1942 the brigade was practically the only army unit in place to protect the Western Australian coastline from the feared Japanese invasion.
Split into simpler sentences: The brigade was reformed in 1939 in response to the outbreak of the Second World War. Up until 1942 the brigade was practically the only army unit in place to protect the Western Australian coastline from the feared Japanese invasion.