> If no one works on defence systems then all the things we have could become jeopardized, perhaps not this week but in 5 years. Therefore I can reconcile the idea of working for defence related r&d.

I am not saying this line of thinking is completely absurd. But I think every individual considering this should reflect a lot. (1) Is your country using its ""defense"" systems wisely? (2) Won't the technology be replicated by adversaries anyways? (3) etc..

Overall, the number of people and resources spent on Weapons R&D is probably significantly more than people working on things like diplomacy, ethics, or activism for international human rights (assuming human rights violations are the only legitimate reason for war).

It's significantly safer for individual nations and humanity as a whole if we're not all armed to the teeth constantly on the brink of large conflict, and instead are more or less ethically aligned, all respect basic human rights, and respect other nations.

I think that there is a difference between wishful thinking about how things should be versus preparing based on how things are.

Also diplomacy doesn't have a great track record for the past 100 years.