If it is war between two countries like the Russia-Ukraine war other countries will benefit from it when it comes to supply of food and other services, their is no way which other countries won't benefit from it.
This is a very narrow view that takes into account only one side and completely ignores the other. Yes, other countries can benefit from supplying weapons to Ukraine. But this aggressive war has already badly affected world markets. Fuel and food prices have risen sharply. All European countries have already experienced this. Business is closing, trade routes are being lost, the tourism sector is suffering. These factors cannot be excluded from the equation. I think they not only compensate possible gains, but also exceed them.