The world is interconnect and war in one region affects other regions. Generally, war threatens global economic stability, potentially resulting in inflation higher prices and slower growth across different sectors. War affects the oil market and leads to adverse economic repercussions potentially causing increased oil prices globally triggering inflation and economic instability worldwide. War also leads to shortages of energy-related commodities influencing prices and growth not only in the region but also in surrounding areas.
War would do far more economic harm than good. Even if we limit the war to conventional arms, and considering who the combatant would be, at minimum we could expect significant destruction across Europe, a serious interruption of trade between the U.S. and China, and shocks to the global oil supply. On the labor front, the prevalence of computer-assisted assembly has ensured there would not be the kind of upswell of manufacturing jobs (ie, weapons suppliers) that would be sufficient to employ the masses of people whose services/financial-dependent jobs crumbled in the economic turndown.
However, war also lead to a significant destruction of infrastructure, building and lives in area that is affected, which requires rebuilding efforts that will take a lot of resources and time. War can also bring the stock market down, nothing good comes out from war we see a typical example with the Israeli and Hamas, both children and adult are not safe from the war.