I don't care if the increase in the national GDP of some countries can be caused by war .....
You have voiced a very subtle topic.
The point is that the GDP of a country that is actively at war may look good on the one hand, but on the other hand you have to realize that during a war the GDP generates products and services that do not create additional value for the economy. Take for example the terrorist country Russia - they claim that the economy is doing well, but in reality the economy is collapsing and the population is poor. Why ? Because about 40% of russia's budget goes to support the terrorist war - ammunition, shells, equipment, ammunition, payments to terrorists of the rf army...... And all this, after a very short time, turns into smoke, burned debris, corpses of their soldiers (and the loss of able-bodied population). So the GDP of a country at war is not equal to the same GDP in peacetime !
I absolutely agree with what you said. To me it's a pity that all people around the world can't (or don't want) understand these simple things. War is bad for any economy of any country that is at war, and it is for the global economy too. Because, like you righly said, many things turn into smoke, burned debris, corpses of their soldiers etc.