if war broke three world then the economy will increasingly fall apart for the cost of the war, if we had not come to terms again.
for what is life?
Look at the second world war. During the war, there was a huge spike in the steel production and some other sectors of the industry. So it is not all negative. There will be some positives, which can benefit the global economy.
War is always destruction. As you know sooner or later, any war ends. Then the economic recovery should stimulate demand for all. This leads to the development of the country. The way of the world.