Can wars bring either advantages or disadvantages or both to impact our economy growth ?In history, I feel that international war can influence any country's economy development has either positive or negative impact in possible. On the inflationary hand, for the First World War economy growth influence example, in the First World War and since most notably the German hyperinflation of the 1920 year, this type of monetary regime shows a far smaller tendency towards inflation. In the First World War period, volatility of inflation and output were higher in the short run. So, First World War had little negative impact to influence world inflation in the war period. However, in the First World War period, the supply of money was determined not by the rates of economic growth only, but by the amount of available gold and could not be adjusted in response to economic needs. So, new sources of gold would increase money supply and inflation and decrease interest rates , the opposite of what modern central banks would do to provide stable economic growth in First World War. So, it explained that the First World War occurrence caused the change from non-inflationary to inflationary long term development. Thus, it seems First World War brings more money supply and gold supply to stable economic growth in the future long term period.On the labor productivity influence hand, leaving monetary issues aside, the First World War created the working time intellectual mood to change labor productivity, it would be a 15-18 hours working week for more enlightened leisure to Europe labors. Some prominent modern economists on the accuracy of the predictions on GDP growth per capital was remarkably accurate given to be fallen down that it was made at the time when economy growth theory did not even exist in the First World War period. Thus, it seems First World War also causes working time to be raised to the developing countries during the industrialization period. Then, the long time working time brought to the developing countries' workers to it is poor for labor health. Hence, although employers can raise productivity, but they need many workers to work long time to cause unhealthy. The majority found that the prediction on leisure is of the variations between world regions , due to income level exist, making European variety of capitalism. So, the First World War caused income inequality within countries and between nation states, trends in working hours , world poverty and ever growing needs ( consumerism) and the like. Thus, the developed western countries' workers can work lesser time to compare to the developing Asia countries' workers. Consequently, First World War brought negative impact to influence the developing Asia countries' worker unhealthy and physical and mental illnesses number had been increasing as well as it brought positive impact to influence the labor productivity had been increasing to the Asia countries' employers, due to their workers need to work long time every day.It seems on the positive impact hand, that the First World War caused the inflation occurrence to bring more money supply and gold supply to be raised to influence global economic growth. But, on the negative impact hand, it also brought low working hours in European developed countries and high working hours to the Asia developing countries which are needed to do different occupations in developing countries as well as the income inequality caused unfair social challenge had also occurred in developed countries, such as Europe, UK, US etc. and developing countries, such as China, Japan, Korea etc.