Since the peaople of all nations are seeking peace, all leaders must conquer the passion for power.
I’m supposed to use an ablative absolute and the passive periphrastic.
I got:
**Populis omnium gentium pacem quaerentibus sunt, cupiditas imperii omnibus ducibus superanda est.**but, in the english sentence, ‘all leaders’ is the subject. In the latin one, it’s not, so I was wondering if the active future participle can be used in kinda the same way:
Populis … sunt, omnes duces cupitidatem imperii superaturi sunt.
just wondering..
salve Deudeditus 
In the ablative absolute, you shouldn’t include ‘sunt’: it’s just understood as part of ‘quaerentibus’, so 'populis omnium gentium pacem quaerentibus: ‘the people of all nations seeking pace’ (literal translation), or ‘[since] the people of all nations [are] seeking peace’: an English subordinate clause, much smoother in English I’ve come to believe.
Your second rendition of the other half of the sentence used the active periphrastic. This, I think, is less a matter of necessity and more a matter of ‘about to do’ ness, rather than ‘it absolutely has to be done’.
Once again, I’d wait for someone with more experience in Latin to confirm.
I concur with nostos. The future active participle can convey purpose, but not obligation; the passive periphrastic, a verb of obligation, or some similar construction should be used.
Thanks for the help. I don’t know why I put sunt in. cursed absent-mindedness!
valete