In the first period, the economy grew only moderately at first and relied heavily on traditional agriculture to finance modern industrial infrastructure. When the Russo-Japanese War began in 1904, 65% of employment and 38% of the gross domestic product (GDP) was still based on agriculture but modern industry had begun to expand substantially. During World War I, Japan used the absence of the war-torn European competitors on the world market to advance its economy, generating a trade surplus for the first time since the isolation in the Edo period.