Again not covered by the EU agreement. Although a few EU members argue strongly for military unification. It was raised by many during brexit as a reason to leave the EU. So again unlikely to find full upport in the near future.

Currently the supply of arms and weapons is totally uncovered by EU trade agreements. NATO has some agreements. But non that cover this.

The thing people forget. International law dose not really exist beyond atual agreements nations are willing to commit to. Unfortunately as the world is a bloody long way from a utopia. Most nations are unwilling to agree to things that limit their own military actions. So nothing most other nations can do.

The closest we ever came is post WW2 where the Geneva convention and ICC was set up.

But as you can see. No nation is forced to abide by such rules. The US and Russia make i clear. Might makes right until some event leaves oa nation on the losing side of a battle with enough losses of resources to need help from other nations.

What the rest of the world thinks in wars is still pretty much unimportant to the events.