I think we've seen over the past decade that countries are really quick to excuse acts of war because they don't want to go to war. See: cyber attacks, novichok

I think we've seen over the past decade that countries are really quick to excuse acts of war because they don't want to go to war. See: cyber attacks, novichok, shooting down civilian airliners, spy balloons, Nordstream 2, ramming into a military drone to crash it. Unless the geoengineering has a clear and large negative effect, or if it were done maliciously (somehow?), I don't see any wars arising. At most a strongly worded letter about how everyone else should have been consulted first.