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.)
Just to play devil's advocate with some arguments against peace (in a not so well thought out way)... There's a book called 'The Great Leveler' which puts forward the hypothesis that the only time when widespread redistribution has happened is after wars. This means that without war we might expect consistently rising inequality. This effect has been due to mass mobilization ('Taxing the Rich' asserts that there has only been mass political willpower to increase redistribution with the claims of veterans having served and feeling they should be compensated) anddestructionn of capital (in Europe much of the capital was destroyed in WW2 -> massive decrease in inequality, US less so on both front) (haven't read the book though). Spinning this further we could be approaching a time where great power war would not have this effect. This is because less labor is required and it would be higher skilled. Perhaps there would be little use for low skilled grunts in near future wars (or already). If we also saw less destruction of capital (maybe information warfare is the way of the future?) Then we lose the mechanisms which made war a leveller in the past. SO we might be in the last time where a great power war (one of the only things we know reduces inequality) would be able to reduce inequality. If inequality continues to increase we could see suboptimal societal values which could continue on indefinitely and/or cause large amount of suffering the mediumrun. This could also lead to more domestic unrest in medium-run which would imply a peace now vs peace later trade-off. Depending on how hingey the moment is for the long-term future now, it could be better to have peace later. ALSO, UN was created post WW2. Maybe we only have appetite for major international cooperation after nasty wars? Anyway... Even after considering that, peace and cooperation is probably good on net, but not as obvious as it may seem. (Wrote this on mobile, sorry for any errors and lack of having read more than a few pages of the books I cited)