Consider all the actions possible tomorrow, which individuals or groups could take. Are there any which would "obviously" (meaning: you believe it with high probability, and you expect that belief to be uncontroversial) result in decreased x-risk?
(For example, consider reducing the size of Russia and the US's nuclear stockpiles. I'm curious if this is on the list.)
(I include "which individuals or groups" could take because I am interested in what actions we could take if we all coordinated perfectly. For example, neither Russia nor the US can unilaterally reduce both their stockpiles, and perhaps it would increase x-risk for one of them to lower only theirs, but the group consisting of US and Russia's government could theoretically agree to lower both stockpiles.)
In this talk on 'Crucial considerations and wise philanthropy', Nick Bostrom tentatively mentions some actions that appear to be robustly x-risk reducing, including promoting international peace and cooperation, growing the effective altruism movement, and working on solutions to the control problem.
Thank you for those references!