Leaders of Eastern nations now usurping islands in the doldrums (5)
I believe the answer is:
ennui
'in the doldrums' is the definition.
(I've seen this before)
'leaders of eastern nations now usurping islands' is the wordplay.
'leaders of' indicates taking the first letters.
The initial letters of 'eastern nations now usurping islands' is 'ENNUI'.
(Other definitions for ennui that I've seen before include "Effect of boredom" , "Feeling of listlessness" , "French boredom and lassitude" , "Boredom, tedium" , "Lower interest rate" .)